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: Aridity presents ____ main obstacles to solitary behavior.\Question: Choose the right answer from options given a) no b) three c) two d) five
Example Output: c

Example Input: Vision problems affect one in ____ school-aged children.\Question: Choose the right answer from options given a) six b) four c) seven d) one
Example Output: b

Example Input: Hoary marmots are active about ____ and a half months each year.\Question: Choose the right answer from options given a) four b) seven c) ten d) eight
Example Output:
a