That the speaker is nervous
i took the test right now
A predicate adjective is the first adjective that follows a linking verb which connects two parts of a sentence (in this case, that verb is 'was'). So, the first adjective after was is 'sleek', so D is the correct answer.
Your answer is "The turnip continued slowly to descend"
I believe the answer is C. An ability to recite the constitution.