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').

Ex Input:
Rock cavies become sexually mature when they are about one to ____ months old.\Question: Choose the right answer from options given a) one b) four c) three d) seven

Ex Output:
c


Ex 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

Ex Output:
b


Ex Input:
Warm fronts have an average speed of about ____ knots, and can move in a series of jumps.\Question: Choose the right answer from options given a) four b) ten c) seven d) nine

Ex Output:

b