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: Evolution is dependent on ____ forces.\Question: Choose the right answer from options given a) no b) five c) two d) seven
Example Output: c

Example Input: Grasshoppers can fly at speeds up to ____ miles per hour.\Question: Choose the right answer from options given a) eight b) seven c) two d) nine
Example Output: a

Example Input: Most babies are ____ years old or more.\Question: Choose the right answer from options given a) two b) ten c) seven d) three
Example Output:
a