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:
Most people have ____ kidneys.\Question: Choose the right answer from options given a) two b) five c) seven d) six

Ex Output:
a


Ex Input:
Alleles fall into ____ classes based on somatic, gonadal and dauer phenotypes.\Question: Choose the right answer from options given a) ten b) six c) eight d) no

Ex Output:
b


Ex Input:
Most miscarriages occur within the first ____ weeks after the last menstrual period.\Question: Choose the right answer from options given a) six b) zero c) no d) eight

Ex Output:

d