Answer:
A. livelier
Step-by-step explanation:
B. liveliest is not the word that can be use properly in this sentence so B is not the answer. C. lively the same go's to C as it does to B these are words that cannot be properly used in this sentence. And for D. more livelier D has a double adjective so its the same as saying 'more gooder' the er in the sentence takes the place of the adjective "more".