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: Redwoods reproduce ____ ways.\Question: Choose the right answer from options given a) zero b) two c) six d) nine
Example Output: b

Example Input: Today there are ____ basic classifications of sausage.\Question: Choose the right answer from options given a) five b) four c) six d) one
Example Output: a

Example Input: Edible fungi occur in ____ major taxonomic groups.\Question: Choose the right answer from options given a) ten b) four c) eight d) two
Example Output:
d