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: Streptomyces are of special interest for ____ reasons.\Question: Choose the right answer from options given a) nine b) seven c) four d) two
Example Output: d

Example Input: Young emus are very vulnerable to disease until they are about ____ months old.\Question: Choose the right answer from options given a) no b) ten c) six d) three
Example Output: d

Example Input: Plants grow ____ to two and a half feet tall.\Question: Choose the right answer from options given a) five b) zero c) seven d) one
Example Output:
d