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').

Input: Consider Input: National immunization vaccinates all children under ____ against polio.\Question: Choose the right answer from options given a) zero b) four c) ten d) five

Output: b


Input: Consider Input: Cleavage is perfect in ____ directions, prismatic.\Question: Choose the right answer from options given a) two b) nine c) three d) seven

Output: a


Input: Consider Input: Chickadees live in family groups of five to ____ members.\Question: Choose the right answer from options given a) no b) six c) nine d) ten


Output: c