I think the correct answer from the choices listed above is the first option. The Greeks were the first to use the term atom. In 450 BCE, Democritus coined the term átomos which means "uncuttable" or "the smallest indivisible particle of matter".
The prefix 'di' means two. Hence two atoms make up a diatomic molecule.
Hope this helps!
The basic building block of matter is the atom.
The answer is B
Vaporization