another writing question~

<li>Recent studies indicate that eating chocolate and other sweets neither cause or aggravate acne.
nailed down to 2
B) neither cause nor aggravate
C) neither causes nor aggravates
the answer is C. i picked B. can someone explain this? is it because "eating…sweets "the whole phrase is singular? or because “acne” is singular? i think acne doesn’t matter in this case. pls explain!</li>
</ol>

<p>Imagine the sentence without the "and other sweets" part. Then read the two choices, and it seems that C is the correct answer.</p>

<p>The verb must match the gerund "eating", not what is being eaten. Eating is singular.</p>