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: Interdigital glands are present on all ____ feet, and are slightly larger on the front feet.\Question: Choose the right answer from options given a) three b) five c) four d) eight
Example Output: c

Example Input: Birds reach sexual maturity in three to ____ years.\Question: Choose the right answer from options given a) seven b) two c) five d) six
Example Output: c

Example Input: Sea cucumbers have between ____ and thirty such tentacles , depending on the species .\Question: Choose the right answer from options given a) two b) one c) three d) ten
Example Output:
d