You are given a sentence and a question. You're expected to write the correct answer based on the sentence.

Example input: Sentence: Jacob and Benny are squatting at the gym. Jacob has thin frail legs and Benny has big strong legs. Question: Who squats less weight?
Example output: Jacob
Example explanation: Typically, people with thin frail legs squat less weight than people with big strong legs, so the answer is Jacob.
Q: Sentence: A dirty tooth isn't as smooth as a clean tooth. Question: Which surface will a toothbrush move over at a greater rate of speed?
A:
clean tooth