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:
Natural tellurium consists of ____ isotopes.\Question: Choose the right answer from options given a) six b) seven c) eight d) one

Ex Output:
c


Ex Input:
Beer is made from fermented grains and has an alcohol content of ____ to six percent.\Question: Choose the right answer from options given a) zero b) three c) two d) ten

Ex Output:
b


Ex Input:
Seeds germinate in about a month, but plants grown from seed take three to ____ years to flower.\Question: Choose the right answer from options given a) five b) no c) nine d) one

Ex Output:

a