What Is the Difference Between an Atom and an Element

What is the difference between an atom and an element?

A) An atom is made of protons, electrons, and (most of the time) neutrons; an element is composed of only one kind of atom.
B) An element is made of protons, electrons, and (most of the time) neutrons; an atom is composed of only one kind of element.
C) An atom does not contain electrons, whereas an element does.
D) An atom contains protons and electrons, whereas an element contains protons, electrons, and neutrons.
E) All atoms are the same, whereas elements differ in structure and properties.