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').

Trains kill ____ people every year.\Question: Choose the right answer from options given a) zero b) three c) no d) four
d

Most infected persons have ____ symptoms of disease.\Question: Choose the right answer from options given a) six b) no c) three d) one
b

Migraine headaches are ____ times more common in women than in men.\Question: Choose the right answer from options given a) three b) no c) two d) four

a