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.
I believe the answer to be C.) Literal and concrete
A dependent clause. Because this sentence only give an action, there is no cause for this action unless given said cause.
