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 can harbor a heartworm infection at any age from ____ months to seventeen years.\Question: Choose the right answer from options given a) one b) six c) nine d) three
Example Output: c

Example Input: Reptiles also have scaly skin and a ____ chambered heart.\Question: Choose the right answer from options given a) zero b) one c) ten d) three
Example Output: d

Example Input: Many calanoid copepods possess ____ different modes of locomotion.\Question: Choose the right answer from options given a) seven b) two c) six d) no
Example Output:
b