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: Most marine sediments are of ____ basic types.\Question: Choose the right answer from options given a) three b) ten c) two d) nine
Example Output: c

Example 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
Example Output: b

Example Input: Ovulation failure accounts for one in ____ cases, as do blocked or diseased fallopian tubes.\Question: Choose the right answer from options given a) six b) two c) five d) ten
Example Output:
c