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: Vampires generally are male, and rabies is ____ times more frequent in men than in women.\Question: Choose the right answer from options given a) no b) two c) zero d) seven

Output: d


Input: Consider Input: Some sources claim there are more like ____ million vertebrate animals in zoos.\Question: Choose the right answer from options given a) six b) five c) one d) three

Output: b


Input: Consider Input: Background radiation comes from ____ sources.\Question: Choose the right answer from options given a) zero b) three c) four d) no


Output: b