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: Vaccinated newborns have protection for at least ____ years.\Question: Choose the right answer from options given a) four b) five c) two d) no

Output: b


Input: Consider Input: Condors become sexually mature at about five or ____ years of age and mate for life.\Question: Choose the right answer from options given a) nine b) seven c) one d) six

Output: d


Input: Consider Input: Immunization is a series of ____ injections.\Question: Choose the right answer from options given a) eight b) ten c) two d) three


Output: d