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: Females have two X-chromosomes, ____ from each parent.\Question: Choose the right answer from options given a) ten b) four c) one d) zero
Example Output: c

Example Input: Orangutans spend up to ____ hours a day eating or foraging for food.\Question: Choose the right answer from options given a) seven b) nine c) three d) six
Example Output: d

Example Input: Primates have ____ digits on their forelimbs.\Question: Choose the right answer from options given a) five b) seven c) ten d) zero
Example Output:
a