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 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: Cooked meat freezes well for up to ____ months.\Question: Choose the right answer from options given a) four b) three c) eight d) five
Example Output: b

Example Input: Kangaroos have ____ such pairs of chewing teeth.Grasslands are wide, open areas.\Question: Choose the right answer from options given a) eight b) two c) three d) four
Example Output:
d