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').

Vision problems affect one in ____ school-aged children.\Question: Choose the right answer from options given a) six b) four c) seven d) one
b

Owls have ____ toes on each foot, like most birds.\Question: Choose the right answer from options given a) no b) seven c) four d) one
c

Milk protein has ____ basic components, whey and casein.\Question: Choose the right answer from options given a) four b) three c) two d) no

c