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').

Input: Consider Input: Chickens take about six to ____ weeks to grow.\Question: Choose the right answer from options given a) eight b) two c) no d) five

Output: a


Input: Consider 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

Output: d


Input: Consider Input: Free trade exists only where there are ____ barriers to voluntary exchange.\Question: Choose the right answer from options given a) four b) eight c) six d) no


Output: d