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:
Indian reservations are part of five of the nation's ____ poorest counties.\Question: Choose the right answer from options given a) seven b) nine c) ten d) two

Ex Output:
c


Ex Input:
Rheumatic fever begins one to ____ weeks after an untreated streptococcal infection.\Question: Choose the right answer from options given a) six b) ten c) two d) zero

Ex Output:
a


Ex Input:
Ozone is an invisible gas composed of ____ atoms of oxygen.\Question: Choose the right answer from options given a) eight b) three c) five d) six

Ex Output:

b