Answer:
C. are found in the nucleus of an atom
Step-by-step explanation:
Protons and Neutrons are always located at the center of the atom also called as the nuclei of the atom and constitute nearly all the mass of the atom, while the electrons revolve around them in orbits called shells. Only protons have a positive charge and electrons have negative charges, due to which only protons and electrons attract each other, while neutrons lack charges or have 'Neutral Charges'.