The correct answer is C. Neutron.
An electron is a subatomic particle with a negative elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron has a mass that is approximately 1/1836 that of the proton.
A proton is a subatomic particle with a positive elementary electric charge. It belongs to the first generation of the hadron particle family, and is generally thought to be a fundamental particle because it has no known
components or substructure. Protons belong to the nuclear particles category of the baryon subcategory. The proton has a mass that is approximately 1836 times that of the electron.A neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton. Protons and neutrons, together known as nucleons, make up the nucleus of an atom. Neutrons are stable within the nucleus, but outside it, they decay with a half-life of about 15 minutes into a proton, an electron, and an antineutrino.
A hydrogen nucleus is a proton.