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').

Ex Input:
Bone marrow replenishes itself fully within ____ weeks.\Question: Choose the right answer from options given a) nine b) no c) one d) two

Ex Output:
d


Ex Input:
Statistics show, however, that men are ____ times more likely to be lefty than women.\Question: Choose the right answer from options given a) four b) three c) nine d) two

Ex Output:
b


Ex Input:
Most dogs can resume normal activity ____ to ten days after surgery.\Question: Choose the right answer from options given a) five b) six c) no d) ten

Ex Output:

a