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: 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: Most infected persons have ____ symptoms of disease.\Question: Choose the right answer from options given a) six b) no c) three d) one
Example Output: b

Example Input: Facets are flat triangles bounded by ____ edges.\Question: Choose the right answer from options given a) nine b) ten c) three d) one
Example Output:
c