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').

Nightmares happen frequently in childhood, especially between the ages of ____ and six.\Question: Choose the right answer from options given a) three b) eight c) no d) ten
a

Clover leaves with ____ to nine leaflets, illustrating a tendency to mutate.\Question: Choose the right answer from options given a) three b) zero c) ten d) five
a

Ozone is a molecule containing ____ oxygen atoms.\Question: Choose the right answer from options given a) one b) nine c) no d) three

d