Blue Book Sentence Correction Error help!

<p>Dr. Ming {has disporved} a widely accepted theory of physics when she showed that identical nuclear particles do not always act alike.</p>

<p>(A) has disproved----> I know this is wrong because has is used for an ongoing action, but in this sentence is it is in the past( when she showed...).Would you replace has with had?</p>

<p>(B) having disproved----->I know this is wrong because it results in a sentence fragment.</p>

<p>(C) Disprove-------> Right answer</p>

<p>(D) Disproves--------> Wrong tense, it should be in past tense</p>

<p>(E) Disproving----------------> I dont know why this is wrong.</p>

<p>C and D are both in the present tense, I don't see why D is wrong and C isn't. E is wrong because 'Disproving' is a gerund, which can only function as nouns (don't think it could be a participle). I actually think that A is correct because 'has' would just be a helping verb and that the actual verb 'disproved' would be in the correct tense.</p>

<p>Yikes!!! Two typos in your transcription of a SAT question. It feels like a puzzle to figure out how to correct the typos. Please take a few seconds to review your posts before you hit the final submit.</p>

<p>The question is this:</p>

<p>Dr. Chien-Shiung Wu (has disproved) a widely accepted theory of physics when she showed that identical nuclear particles do not always act alike.
A) has disproved
B) having disproved
C) disproved
D) disproves
E) disproving</p>

<p>And the answer is (C). The cue for the simple past is the word "when". There may be an argument that the past perfect may also be appropriate. But it's not one of the choices.</p>

<p>For poster #2, it can't be "has proved" (the present perfect) because that would mean that the action of proving continues into the present. Clearly that's not the case. The "when" makes clear that it is done.</p>