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: Heat pumps give off ____ fumes or harmful products of combustion.\Question: Choose the right answer from options given a) four b) zero c) six d) no
Example Output: d

Example Input: Hydra has ____ distinct methods of reproduction, asexual and sexual.\Question: Choose the right answer from options given a) two b) zero c) no d) ten
Example Output: a

Example Input: Dust takes place over ____ days, split into morning, afternoon, and evening.\Question: Choose the right answer from options given a) five b) seven c) ten d) four
Example Output:
a