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: Fryers have ____ thermostats.\Question: Choose the right answer from options given a) five b) three c) two d) one
Example Output: c

Example Input: Orangutans spend up to ____ hours a day eating or foraging for food.\Question: Choose the right answer from options given a) seven b) nine c) three d) six
Example Output: d

Example Input: Dew worms can tunnel as deep as ____ feet.\Question: Choose the right answer from options given a) no b) five c) two d) one
Example Output:
b