Atoms of the Same Element Can Exist in Different Forms

Atoms of the same element can exist in different forms called isotopes. The most common isotope of carbon is carbon-12 but it has two less-common isotopes, carbon-13 and carbon-14. The less-common isotopes have

A) the same number of electrons but more protons.
B) the same number of protons but more neutrons.
C) the same number of neutrons but more protons.
D) the same number of protons but more electrons.
E) the same number of neutrons but more electrons.