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: Women are ____ times as likely as men are to develop osteoporosis.\Question: Choose the right answer from options given a) zero b) four c) one d) nine
Example Output: b

Example Input: Metabolism have ____ stages-catabolism and anabolism.\Question: Choose the right answer from options given a) nine b) two c) five d) three
Example Output: b

Example Input: Fibreoptic systems have an effective life ____ times that of copper.\Question: Choose the right answer from options given a) no b) five c) one d) three
Example Output:
d