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: Guinea has ____ territories or colonies.\Question: Choose the right answer from options given a) no b) seven c) three d) eight
Example Output: a

Example Input: Many tortoises can retract their head, their ____ limbs and tail into the shell for protection.\Question: Choose the right answer from options given a) no b) one c) two d) four
Example Output: d

Example Input: Females like to care for ____ to four babies at a time because one cub is a waste of time.\Question: Choose the right answer from options given a) three b) seven c) six d) one
Example Output:
a