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:
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:
Manatees swim two to ____ miles per hour.\Question: Choose the right answer from options given a) no b) six c) five d) zero

Ex Output:
b


Ex Input:
Beryllium has ____ protons and four electrons.\Question: Choose the right answer from options given a) three b) one c) four d) six

Ex Output:

c