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: Turkish citizens can enter Bosnia and stay up to ____ months without a visa.\Question: Choose the right answer from options given a) five b) seven c) four d) three
Example Output: d

Example Input: Sports bras come in ____ basic styles.\Question: Choose the right answer from options given a) five b) six c) two d) zero
Example Output: c

Example Input: Willow flycatchers have a lifespan of three to ____ years.\Question: Choose the right answer from options given a) no b) seven c) four d) two
Example Output:
c