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').

Example Input: Children now account for only ____ percent of all forest fires caused in the United States.\Question: Choose the right answer from options given a) five b) four c) eight d) nine
Example Output: b

Example Input: Human females have ____ X chromosomes.\Question: Choose the right answer from options given a) two b) six c) one d) eight
Example Output: a

Example Input: Most big cats can pull with ____ times as much force as the same weight of human athletes.\Question: Choose the right answer from options given a) five b) eight c) three d) one
Example Output:
a