SAT Writing Question, please help!

<p>The harmful effects of smoking on the vascular system [is increasingly well documented].</p>

<p>A) is increasingly well documented
B) is more and more documented
C) are increasingly well documented
D) are increasing in better documentation
E) has increased in better documentation</p>

<p>The answer is C but I put D because the sentence itself sounded awkward with C. Can someone please explain why it's C and not D?</p>

<p>First of all, great job knowing that it was “are” and not “is” because a lot of people get confused on that. Now the reason it’s C is because C actually sounds less awkward than D. Remember the SAT likes conciseness and straightforwardness. Also, the original (wrong) sentence said “increasingly well documented” and usually my rule of thumb is to not change the meaning of the sentence. By that I mean do change the part that is clearly wrong, the “is” but if nothing else really stands out or everything else makes sense, even if you don’t think so, let it be.</p>

<p>Thank you so much! :)</p>