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: Most herbal formulas contain ____ to twelve herbs in various combinations.\Question: Choose the right answer from options given a) four b) no c) seven d) six
Example Output: d

Example Input: Most Trusts have ____ or more Trustees.\Question: Choose the right answer from options given a) zero b) nine c) ten d) two
Example Output: d

Example Input: Cuckoos live less than ____ years in the wild.\Question: Choose the right answer from options given a) eight b) six c) two d) three
Example Output:
b