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: Pups remain in the den for about ____ weeks, and are cared for by the entire pack.\Question: Choose the right answer from options given a) ten b) three c) six d) no
Example Output: c

Example Input: Some people try to count to ____ when they feel angry.\Question: Choose the right answer from options given a) no b) ten c) seven d) five
Example Output: b

Example Input: Head lice can survive three to ____ days once dislodged from the host.\Question: Choose the right answer from options given a) no b) one c) four d) eight
Example Output:
c