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: All baleen whales have ____ blow holes.\Question: Choose the right answer from options given a) zero b) four c) seven d) two
Example Output: d

Example Input: Righteousness always points in ____ directions.\Question: Choose the right answer from options given a) six b) two c) one d) four
Example Output: b

Example Input: Spectal quality affects disease development of ____ pathogens on hydroponically grown plants.\Question: Choose the right answer from options given a) nine b) three c) ten d) five
Example Output:
b