Given that oxygen-16 and oxygen-18 both have an atomic number of 8, how many electrons, protons, and neutrons do these oxygen atoms contain?
 A.Both oxygen isotopes contain 8 electrons and 8 protons but each contains a different number of neutrons - 8 and 10 respectively.
 B.The oxygen isotopes contain 8 electrons but each contains a different number of neutrons and protons - 8 and 10 respectively.
 C.These oxygen configurations contain the same number of subatomic particles - 8 electrons, 6 protons and 10 neutrons.
 D.Any oxygen atom contains 8 electrons and 9 neutrons but these vary in the number of protons - 8 and 10 respectively.