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: Genetic mapping divides the chromosomes in ____ bands.\Question: Choose the right answer from options given a) ten b) two c) four d) nine
Example Output: b

Example Input: Giraffes sleep less than ____ hours a day.\Question: Choose the right answer from options given a) two b) six c) seven d) ten
Example Output: a

Example Input: Most species have ____ sexes - male and female.\Question: Choose the right answer from options given a) zero b) one c) two d) eight
Example Output:
c