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').

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

Ex Output:
d


Ex Input:
Death occurs during the first ____ days of illness without intensive care.\Question: Choose the right answer from options given a) seven b) eight c) five d) nine

Ex Output:
a


Ex Input:
Scientists think that macaws mate for life, producing ____ to three young each year.\Question: Choose the right answer from options given a) one b) no c) two d) five

Ex Output:

a