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 toddlers find it hard to sit still for more than a few seconds, let alone ____ minutes.\Question: Choose the right answer from options given a) no b) three c) four d) zero
[A]: b


[Q]: Rock cavies become sexually mature when they are about one to ____ months old.\Question: Choose the right answer from options given a) one b) four c) three d) seven
[A]: c


[Q]: Insects have three pairs and arachnids have ____ pairs of limbs.\Question: Choose the right answer from options given a) no b) four c) nine d) five
[A]:
b