What does the term "basic unit of matter" refer to?

A.) Atoms

B.) Elements

C.) Molecules

I think the correct answer from the choices listed above is option A. Atoms is referred to as the basic unit of matter. It is present in all phases and in every object. It consists of electrons, protons and neutrons in which these particles cannot present alone as it is.

A. Atoms - Atoms are the basic units of matter and the defining structure of elements. Atoms are made up of three particles: protons, neutrons and electrons.