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:
Lung disease is America's number three killer, responsible for ____ in seven deaths.\Question: Choose the right answer from options given a) five b) nine c) one d) four

Ex Output:
c


Ex Input:
Young children suffer from an average of six to ____ colds a year.\Question: Choose the right answer from options given a) ten b) eight c) two d) one

Ex Output:
b


Ex Input:
Water lilies can grow in water as shallow as ____ inches and as deep as fifteen feet.\Question: Choose the right answer from options given a) nine b) two c) zero d) six

Ex Output:

d