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').

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
b

Water is the only natural substance which exists in all ____ states of matter in nature.\Question: Choose the right answer from options given a) no b) eight c) six d) three
d

Bats sometimes emerge up to ____ hours before sundown, forming dense columns over the hills.\Question: Choose the right answer from options given a) six b) nine c) four d) three

d