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: Cats have ____ toes on their front paws, but only four touch the ground when walking.\Question: Choose the right answer from options given a) six b) nine c) five d) zero
Example Output: c

Example Input: Some infected horses show ____ signs and become chronic carriers of the disease.\Question: Choose the right answer from options given a) nine b) six c) four d) no
Example Output: d

Example Input: Culms bear ____ to six leaves.\Question: Choose the right answer from options given a) no b) seven c) four d) five
Example Output:
c