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').

[Q]: Most children experience at least one episode by the time they are ____ years old.\Question: Choose the right answer from options given a) eight b) one c) ten d) seven
[A]: d


[Q]: Uncontrolled diabetes can increase risk by up to ____ times.\Question: Choose the right answer from options given a) five b) four c) seven d) eight
[A]: b


[Q]: Natural oxygen is a mixture of ____ isotopes.\Question: Choose the right answer from options given a) seven b) nine c) three d) six
[A]:
c