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: Gases are perhaps the best understood of the ____ states of matter.\Question: Choose the right answer from options given a) three b) five c) nine d) zero
Example Output: a

Example Input: Some European countries require ____ years of education.\Question: Choose the right answer from options given a) no b) nine c) six d) three
Example Output: d

Example Input: Lynx consume one or ____ hares a day.\Question: Choose the right answer from options given a) five b) no c) two d) three
Example Output:
c