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: Mothers typically have from one to ____ cubs, which are born blind and toothless.\Question: Choose the right answer from options given a) six b) zero c) four d) seven
Example Output: a

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: Baseball has ____ eras.\Question: Choose the right answer from options given a) three b) five c) two d) one
Example Output:
a