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

Answer: b


Question: Twin souls are the last ____ souls to individualize.\Question: Choose the right answer from options given a) two b) ten c) zero d) six

Answer: a


Question: Marshes are shallow wetlands less than ____ meters deep.\Question: Choose the right answer from options given a) five b) zero c) two d) four

Answer:
c