You would use a Dictionary. Dictionaries show denotative meanings while thesauruses show synonyms.
C. Perfectly is the adverb in the sentence.
An adverb modifies a verb, adjective, or another adverb. In this sentence, the word 'perfectly' is modifying the verb 'bakes.'
My first choice would be A. When you read the excerpt, how does it make you feel? That's your first clue to the answer. If they want something book specific, I would choose C.
