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: Atoms are extremely small, on the order of a few ____ billionths of a meter.\Question: Choose the right answer from options given a) ten b) seven c) nine d) eight

Output: a


Input: Consider Input: Metabolism have ____ stages-catabolism and anabolism.\Question: Choose the right answer from options given a) nine b) two c) five d) three

Output: b


Input: Consider Input: Nobodies have ____ emotions , but want to have hearts again .\Question: Choose the right answer from options given a) no b) ten c) five d) one


Output: a