Given a sentence with a missing word, pick the answer option that best fills out the missing word in the sentence. Indicate each answer with its index ('a', 'b', 'c', 'd').

Input: Consider Input: Ocular dryness responds to the use of artificial tears applied every ____ to three hours.\Question: Choose the right answer from options given a) no b) one c) three d) eight

Output: b


Input: Consider Input: Youth unemployment is ____ times the adult level.\Question: Choose the right answer from options given a) one b) three c) seven d) no

Output: b


Input: Consider Input: Humans are bipedal, which means they walk on ____ legs.\Question: Choose the right answer from options given a) nine b) two c) ten d) six


Output: b