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: Quadrupeds are animals with ____ feet, such as cows.\Question: Choose the right answer from options given a) four b) six c) ten d) two

Output: a


Input: Consider Input: Most females are sexually mature at about ____ to six years.\Question: Choose the right answer from options given a) eight b) nine c) five d) two

Output: c


Input: Consider Input: Earth has ____ main layers, crust, mantle, and a core.\Question: Choose the right answer from options given a) two b) three c) nine d) one


Output: b