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:
Genetic mapping divides the chromosomes in ____ bands.\Question: Choose the right answer from options given a) ten b) two c) four d) nine

Ex Output:
b


Ex Input:
Matter exists in ____ forms, solid, fluid and plasma.\Question: Choose the right answer from options given a) ten b) nine c) three d) five

Ex Output:
c


Ex Input:
Autism is a developmental disability that typically appears during the first ____ years of life.\Question: Choose the right answer from options given a) one b) six c) five d) three

Ex Output:

d