According to the modern atomic theory, are atoms divisible?

Atoms are divisible contrary to the early beliefs that the smallest "indivisible" matter is an atom. When an atom loses its identity it means that they are divisible. Atoms chemically react with other kinds of atoms thus changing their activity. During a chemical reaction, there is an exchange of electrons.

The answer is b because c don't explain why the moths are on them and it isn't a because as we know only one species of moth does this