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: Ocular dryness responds to the use of artificial tears applied every ____ to three hours.\Question: Choose the right answer from options given a) no b) one c) three d) eight
Example Output: b

Example Input: Lizards generally have ____ legs and movable eyelids.\Question: Choose the right answer from options given a) four b) two c) five d) zero
Example Output: a

Example Input: Eland milk has almost ____ times the fat and double the protein of milk from dairy cows.\Question: Choose the right answer from options given a) six b) ten c) one d) three
Example Output:
d