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 sometimes neutrons; an element is a substance composed of only one kind of atom.
B) An element is made of protons, electrons, and sometimes neutrons; an atom is a substance 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) None of the above