C. who or what the passage is about
Answer: Hardly
Explanation: Averbs tell: how, when, where, why. An adverb is often formed by adding ly to an adjective.
The italicized noun clause is used as B. direct object in this sentence.
It is relatively easy to spot a direct object in a sentence - just ask the question what/whom? So - What did I find? - What I was looking for.
There is no subject complement here, and the subject is the pronoun I.