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 endocrinologists see patients every ____ months throughout the pregnancy.\Question: Choose the right answer from options given a) six b) two c) zero d) three
Example Output: b

Example Input: Whales are divided into ____ categories, based on their teeth.\Question: Choose the right answer from options given a) two b) four c) nine d) ten
Example Output: a

Example Input: Silver is ____ times more abundant than gold.\Question: Choose the right answer from options given a) nine b) no c) ten d) five
Example Output:
c