9

Set 16: Boundaries

Explanation

Answer: C

PASSAGE

The document, which was extensively analyzed, _______ recently.

Which choice completes the text so that it conforms to the conventions of Standard English?

A. been discovered
B. discovering
C. was discovered✓ Correct
D. were discovered

Detailed Answer Explanation

The correct answer is 'was discovered' because of the rule: passive voice agreement. Passive voice on the SAT requires attention to both verb form and agreement. Ensure the helping verb (was/were, is/are, has been/have been) matches the subject's number, even when modifying phrases intervene.

Key Evidence:

• "The document, which was extensively analyzed, _______ recent..."

Why others are wrong: A ('been discovered' lacks the auxiliary verb "has" or "had" needed to complete the verb phrase), B ('discovering' is active voice and creates an incomplete sentence), D ('were discovered' uses plural "were" with a singular subject).