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 Q]: Decapod crustaceans have ____ pairs of limbs.\Question: Choose the right answer from options given a) five b) four c) six d) seven
[EX A]: a

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

[EX Q]: Plant shrubs three to ____ feet apart in rows six feet apart.\Question: Choose the right answer from options given a) six b) nine c) four d) two
[EX A]:
c