In addition to her work on the Miocene hominid fossil record, Mary Leakey contributed to archaeology with her discovery of the earliest direct evidence of hominid activity and painstakingly documenting East African cave paintings.
A. Leakey contributed to archaeology with her discovery of the earliest direct evidence of hominid activity and painstakingly documenting
B. Leakey contributed to archaeology by her discovery of the earliest direct evidence of hominid activity and by painstakingly documenting
C. Leakey was a contributor to archaeology with her discovery of the earliest direct evidence of hominid activity and with her painstaking documentation of
D. Leakey’s contributions to archaeology include her discovery of the earliest direct evidence of hominid activity and her painstaking documentation of
E. Leakey’s contributions to archaeology include her discovering the earliest direct evidence of hominid activity and painstaking documentation of
OA is D

In addition to her work on the Miocene hominid fossil record, Mary Leakey contributed to archaeology through her discovery of the earliest direct evidence of hominid activity and through her painstaking documentation of East African cave paintings.
A. Mary Leakey contributed to archaeology through her discovery of the earliest direct evidence of hominid activity and through her painstaking documentation of
B. Mary Leakey contributed to archaeology by her discovery of the earliest direct evidence of hominid activity and painstakingly documenting
C. Mary Leakey was a contributor to archaeology by discovering the earliest direct evidence of hominid activity and with her painstaking documentation of
D. Mary Leakey's contributions to archaeology include her discovery of the earliest direct evidence of hominid activity and painstakingly documenting
E. Mary Leakey's contributions to archaeology include her discovering the earliest direct evidence of hominid activity and painstaking documentation of
OA is A.
why A?
Thanks

Parallelism for both of them. Each sentence offers three things that Mary Leakey did. Each list requires parallelism.

In the first one, A gives us "contributed with her (X) discovery and (Y) documenting" Discovery and documenting are ot parallel - nix. Also eliminate B.
C is passive and uses "was a contributor with" which isn't the correct idiom (can also elim A for this reason).
E uses "her (X) discovering and (Y) documentiation" Not parallel.
D correctly says "her (X) discovery and (Y) documentation"

Try the second one now using the lessons above - I'll also add that A, the correct answer, uses the correct idiom "contributed (to archaelogy) through"

Let us know if you still have questions!

_________________
Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT

Thanks
In the first question, Leakey’s contributions (D). In the second question, Mary Leakey contributed (A), while the first phrase is the same. I do not know why?
Could you help me know this?
Thank you very much

in the first question, option C is passive? how? what makes it passive? thanks

Tarek: sorry - I shouldn't have said passive - I was referring to the "Mary Leakey was a contributor with..." which is much more awkward than just saying "Mary Leakey contributed..." The first takes the action out of the verb, the second makes the action the verb.

Vietst: these two questions are a great example of how you can write a sentence correctly in many different ways. There isn't just one right way to write a sentence - don't get hung up on the fact that the correct form is different in the two examples. The only way to answer your question "I do not know why" is to say: they're both grammatically correct. Concentrate on finding the errors (in the other choices) and just know that there isn't only one right way to construct a sentence.

_________________
Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT

So does this mean that the phrase "In addition to her work on the Miocene hominid fossil record" can refer to either "Mary Leakey's contributions" or "Mary Leakey" and still be correct?

I got the second question wrong on GMATPREP because I thought the phrase must refer to "Mery Leakey's contributions" and not just "Mary Leakey". Would someone explain why the phrase can refer to either of them?

What is her referring in the both of the sentence ?

i think you're referring to something along these lines:
coming home from school, the wind blew me off my bike.
--> this sentence is wrong, because "coming home from school" is taken to refer to the wind.

apparently this isn't the same sort of thing.
if these problems are really both official (which would be weird), then i would abstract the following lesson:
the strict application of the opening phrase to the immediately following subject is, apparently, limited to cases in which the opening phrase contains a PARTICIPLE (-ing, -ed), etc.
since this sentence starts with a prepositional phrase (in addition to), not a participle, it apparently doesn't follow the same rule.

note my copious use of the word "apparently"; i'm learning lessons from this problem, just as you are.

it's a possessive pronoun, not an object pronoun. it means the same thing as "mary leakey's".

incidentally, this is the same meaning shared by the other instances of "her" in this sentence.