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').

Example Input: Bucks grow antlers each year that reach ____ to six feet in spread.\Question: Choose the right answer from options given a) seven b) one c) three d) five
Example Output: d

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

Example Input: Young horses spend their first ____ or five years with very little contact with humans.\Question: Choose the right answer from options given a) four b) nine c) two d) six
Example Output:
a