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 linguists organize the African languages into ____ major language families.\Question: Choose the right answer from options given a) three b) four c) eight d) no
Example Output: b

Example Input: Calves are born ____ and a half months after mating.\Question: Choose the right answer from options given a) six b) ten c) eight d) two
Example Output: c

Example Input: Radioactive waste is deposited in ____ concrete tanks within a fenced area.\Question: Choose the right answer from options given a) eight b) three c) four d) five
Example Output:
c