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: 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: Spores have ____ combinations of sexes.\Question: Choose the right answer from options given a) four b) five c) seven d) three
Example Output: a

Example Input: Butterflies have a complex life cycle that consists of ____ different stages.\Question: Choose the right answer from options given a) seven b) four c) nine d) two
Example Output:
b