The atomic number of carbon is six, which means that a carbon atom has six protons. Carbon has three naturally occurring isotopes: carbon-12, carbon-13, and carbon-14. Which of these statements are true about carbon and its isotopes? Select all that apply.

A. All carbon atoms have six neutrons.
B. All carbon atoms have six protons and six electrons.
C. Atoms of all carbon isotopes have either more than 6 electrons or fewer than
6 electrons.
D. Atoms of some naturally occurring carbon isotopes may have six neutrons.
E. Atoms of some naturally occurring carbon isotopes may have twelve neutrons.