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: Prairie dogs bear four or ____ young per litter.\Question: Choose the right answer from options given a) five b) eight c) two d) zero

Output: a


Input: Consider Input: Female cats come into heat cycles every ____ to four weeks during certain times of the year.\Question: Choose the right answer from options given a) eight b) ten c) zero d) three

Output: d


Input: Consider Input: Eccentricity divides double stars into ____ distinct populations.\Question: Choose the right answer from options given a) two b) nine c) no d) six


Output: a