Having more than the usual numbers of fingers or toes on the hands or feet is termed polydactyly.

A.

B. Having had more than the usual number of fingers or toes

C. Having more than the usual number of fingers or toes

D. To have more than the usual number of fingers or toes

E. To have more than the usual numbers of fingers or toes

confused between C and D. In fact I have two questions:

1. the actual confusion is when to use gerund and when to use infinitive.

2. the explanation says that "parallelism" is an issue here. could someone please elaborate?

Thanks
na

I think C is correct.

to X is to Y, Xing is Y
Ordinarily, the “to X” verb form (the infinitive) is not used as the subject of a sentence (which must be a noun). The correct subject form of a verb is called a gerund, which ends in -ing.
Running is aerobic exercise.

There is, however, a special case, when one infinitive is equated to another.
To know me is to love me.

An infinitive may also be part of an introductory phrase (note that it is not then the subject of the sentence).
To learn more, visit our Web site.

But the “To X is Y” construction is incorrect.

Wrong
To have only one medical facility in a city that size is dangerous.
Right
Having only one medical facility in a city that size is dangerous.

Sentence has “Numbers of “and Participle vs. Infinitive issue

To have more than the usual number of fingers or toes on the hands or feet is termed polydactyly.

A. Having more than the usual numbers of fingers or toes [Numbers of – incorrect usage – eliminate]

B. Having had more than the usual number of fingers or toes [ Incorrect use of “Had” – eliminate it]

C. Having more than the usual number of fingers or toes [ Hold it]

D. To have more than the usual number of fingers or toes [Hold it]

E. To have more than the usual numbers of fingers or toes [Numbers of – incorrect usage – eliminate]

Between C and D:
I am guessing X more than Y [ where X and Y needs to be parallel – in this case noun parallel]

C: Having – participle form functions as adjective – eliminate it

D – Hold it

Answer: D

to have = verb
having = verb acting as noun = gerund
for parallelism, we should pick gerund (noun)

My Gmat Progress tracker: d4dial@blogspot.com

This question has been discussed earlier, but not with any definitive conclusion. I will raise it up again for discussion among our ranks. Thanks.

http://www.manhattangmat.com/forums/gerund-vs-infinitive-t3133.html

Rey