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: 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: Sexual reproduction is varied in ____ ways.\Question: Choose the right answer from options given a) seven b) two c) five d) three
Example Output: d

Example Input: Ringtails have furry feet with hairless pads, and each has ____ toes, with semi-retractable claws.\Question: Choose the right answer from options given a) nine b) no c) five d) four
Example Output:
c