The answer should be "slow" the first pairing both end in "-est" making them superlatives giving a parallel in the structure. Following the same structure, the words from the pairing after can be ignored, the word dim is an adjective, "light" bulb is a noun, therefore, it is not a parallel structure.
Probably B. Having been informed
All of them have a verb phrase! a verb phrase is the phrase with the verb, here are the relevant ones:
<span>A. shall be (all that I am and more).
B. was a (collector of memorabilia_.
C. roared (as the bull charged).
D. believed (every word he said).
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