GMAT Verbal & Essays

The major areas of medicine in which lasers are effective is in the cutting and closing of blood vessels, and in the destruction of tumors.
(A) is in the cutting and closing of blood vessels, and in the destruction
(B) are the cutting and closing of blood vessels, and also the case of destroying
(C) are the cutting, closing of blood vessels, and in the destroying
(D) are the cutting and closing of blood vessels, and the destruction
(E) is in the cutting and closing of blood vessels, and the destroying


OA D
[spoiler]I think that the comma should not be present before "and' in option D[/spoiler]

Two issues here:
1. the subject is "areas" so the verb needs to be plural - knocks out A and E
2. the list needs to be parallel - knocks out B and C

answer D

Tani,

what about the comma before AND in OA, which is D?
is that correct: "(A and B), and C"? i think it should be "(A and B) and C"

or it is just a matter of style to put a comma in such a situation, i mean that the writer wanted to emphasize or even separate the two objects 1) (A and B) and 2) C with a very brief pause in speaking that helps to make meaning clearer. does that make sence?

Thanks in advance

You could certainly leave the comma out and some would say it is incorrect. Here, other errors rule out the rest of the choices. I probably wouldn't use it, but sometimes it is helpful when the objects listed are complex phrases rather than simple nouns.