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: Most bioluminescence is blue for ____ reasons.\Question: Choose the right answer from options given a) seven b) two c) four d) zero
Example Output: b

Example Input: Mountain goats have ____ sharp horns.\Question: Choose the right answer from options given a) two b) six c) ten d) four
Example Output: a

Example Input: Pupae usually transform into adults two to ____ days later.\Question: Choose the right answer from options given a) ten b) seven c) zero d) three
Example Output:
d