Which of these is a composite number A 0 B 19 C 1 D 63?

63 is a composite number.

That's because a composite numbers is any positive number which is not a "Prime number". This means that a composite number can be divided exactly by another number which is not 1 or the number itself.

So 63 is a composite number because it can be divided exactly by 3, by 7, by 9, and by 21.

A "composite" of any kind is made up of parts, just like a composition in music has been composed by a composer.