Which statement best describes why an element's atomic number is different from its atomic mass?

A. The atomic number represents the number of electrons, while the atomic mass represents the total mass of the protons and neutrons.

B. The atomic number represents the number of protons, neutrons, and electrons, while the atomic mass represents the total mass of the protons, neutrons, and electrons.

C. The atomic number represents the number of protons, while the atomic mass represents the total mass of the protons, neutrons, and electrons.

D. The atomic number represents the number of protons, while the atomic mass represents the total mass of the protons and electrons.