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:
Some infected horses show ____ signs and become chronic carriers of the disease.\Question: Choose the right answer from options given a) nine b) six c) four d) no

Ex Output:
d


Ex Input:
Embryos develop and hatch in about four weeks, then spend four to ____ months in the tadpole stage.\Question: Choose the right answer from options given a) five b) nine c) eight d) two

Ex Output:
a


Ex Input:
Osteoporosis affects one in ____ women and one in ten men.\Question: Choose the right answer from options given a) eight b) three c) six d) four

Ex Output:

b