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: Springtails reproduce quickly usually within three to ____ weeks.\Question: Choose the right answer from options given a) five b) six c) nine d) three

Output: a


Input: Consider Input: Many tractors have ____ wheel drive to get extra grip on the hills and in wet conditions.\Question: Choose the right answer from options given a) four b) seven c) five d) two

Output: a


Input: Consider Input: Calves begin to take a few fish at about ____ to four months.\Question: Choose the right answer from options given a) three b) six c) four d) no


Output: a