The correct answer is B. Zero.
A hydrogen atom has one proton in its nucleus and one electron orbiting the nucleus. The number of protons in the nucleus determines the chemical element, and the number of electrons determines the chemical properties of the atom. The number of neutrons in the nucleus can vary, and atoms with the same number of protons but different numbers of neutrons are called isotopes. The most common isotope of hydrogen is protium, which has no neutrons.
Option A is incorrect because a hydrogen atom has one proton in its nucleus.
Option C is
incorrect because a hydrogen atom has one proton in its nucleus, not two.Option D is incorrect because a hydrogen atom has one proton in its nucleus, not three.