Most of the purported health benefits of tea comes from antioxidants-compounds also found in beta carotene, vitamin E, and vitamin C that inhibit the formation of plaque along the body's blood vessels.

A)comes from antioxidants-compounds also found in beta carotene, vitamin E, and vitamin C that
Heath benefits (subject, plural) -- come (plural)
B)comes from antioxidants-compounds that are also found in beta carotene, vitamin E, and vitamin C, and they
Heath benefits (subject, plural) -- come (plural)
C)come from antioxidants-compounds also found in beta carotene, vitamin E, and vitamin C and

here compounds is used as abstract noun and missing that is making the sentence awkward.

D) come from antioxidants-compounds that are also found in beta carotene, vitamin E, and vitamin C and that
Correct
E)come from antioxidants-compounds also found in beta carotene, vitamin E, and vitamin C, and they
They is not having a clear antecedent. It may refer to compounds or beta carotene, vitamin E, and vitamin C

Why is choice D correct? Would it be correct without both uses of "that"

Most of the purported health benefits of tea comes from antioxidants-compounds also found in beta carotene, vitamin E, and vitamin C that inhibit the formation of plaque along the body's blood vessels.

A)comes from antioxidants-compounds also found in beta carotene, vitamin E, and vitamin C that
INCORRECT; SVA ERROR

B)comes from antioxidants-compounds that are also found in beta carotene, vitamin E, and vitamin C, and they
INCORRECT; SVA ERROR

C)come from antioxidants-compounds also found in beta carotene, vitamin E, and vitamin C and
INCORRECT; parallelism issue - found is adjective & inhibit is a verb

D) come from antioxidants-compounds that are also found in beta carotene, vitamin E, and vitamin C and that

E)come from antioxidants-compounds also found in beta carotene, vitamin E, and vitamin C, and they
INCORRECT; "they" is redundant as compounds is already the subject

Thanks for your reply as well. Would answer choice D be correct if it lacked the final "that" in the answer choice?

This is QID 2307 in the GMATFix Solutions Engine (full solution here)

without the "that" at the end of D, the sentence would be weaker; probably not strong enough to be a correct answer.

In parallel structures, introductory words can be implied:
Ex 1: I gave you a tool that facilitates your work and that improves your efficiency
Ex 2: I gave you a tool that facilitates your work and improves your efficiency

Both of these examples are right; the "that" can be implied without making the sentence any harder to understand. However, as the sentence becomes longer and more complex, and the two instances of "that" get farther apart, it becomes increasingly important to explicitly repeat "that" to make the parallel structure clear and the sentence easy to understand.

in this sentence, choice D is better for having "that" at the end because it makes it clear that the ending ("that inhibit...") is paired with "that are also found...".

In short, the farther apart the two parallel parts are, the more important it is to be explicit in order to make the sentence easier to understand.

2010Chick wrote:Thanks for your reply as well. Would answer choice D be correct if it lacked the final "that" in the answer choice?

D) come from antioxidants-compounds that are also found in beta carotene, vitamin E, and vitamin C and that

We would need "that to maintain parallelism .... compounds that are .... and that ....