Answer:
The correct answer is D) farther.
Step-by-step explanation:
The word "farther" is a superlative adjective because it is used to compare the distance that the ball travels to other distances. It indicates that the ball travels the greatest distance of all. The other words in the sentence are not superlative adjectives. "Smallest" and "bigger" are comparative adjectives, while "heartily" is an adverb that describes the manner in which the ball is hit.