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: Sexual maturity is reached at about ____ years of age.\Question: Choose the right answer from options given a) five b) ten c) no d) two

Output: d


Input: Consider Input: Mountain goats have ____ sharp horns.\Question: Choose the right answer from options given a) two b) six c) ten d) four

Output: a


Input: Consider Input: Some motors contain ____ gears and spin very fast, and have little if any torque.\Question: Choose the right answer from options given a) four b) three c) five d) no


Output: d