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]: Young squirrels remain in the nest for about ____ weeks.\Question: Choose the right answer from options given a) seven b) six c) two d) eight
[A]: b


[Q]: Nodes are points in space that have ____ probability for locating an electron there.\Question: Choose the right answer from options given a) no b) six c) zero d) three
[A]: c


[Q]: Most people remove ashes every two to ____ weeks.\Question: Choose the right answer from options given a) zero b) one c) three d) no
[A]:
c