As with those of humans, the DNA of grape plants contains sites where certain unique sequences of nucleotides are repeated over and over.
A. As with those of humans, the DNA of grape plants contains sites where
B. As human DNA, the DNA of grape plants contain sites in which
C. As it is with human DNA, the DNA of grape plants, containing sites in which
D. Like human, the DNA of grape plants contain sites where
E. Like human DNA, the DNA of grape plants contains sites in which

This is GMATPREP question. What is the correct answer and why? What is wrong in choice "A"?

the correct answer is e.
- proper subject-verb agreement ('dna of grape plants' is singular, and so 'contains' is the correct form)
- good parallelism: like human DNA (a noun), the DNA of grape plants (a noun) contains...
- correct use of 'like' instead of 'as': 'like' is used with nouns or noun phrases (as it is used here), while 'as' is used with CLAUSES (things that contain verbs, as in 'as it is used here').


- 'those of' doesn't refer to anything (it would need to refer to something plural, and there's nothing plural for it to refer to)
- 'with' serves no grammatical purpose, and destroys parallelism because 'with' dosen't appear in the second part
- 'as' should be 'like'