Answer: Option (A) is the correct answer.
Explanation:
Each atom consists of three sub-atomic particles which are protons, neutrons and electrons.
And, inside the nucleus of an atom, there will be only protons and neutrons. Whereas electrons revolve around the nucleus of an atom.
Protons have a positive charge, neutrons have no charge and electrons have a negative charge.
Therefore, we can conclude that the correct labeling for the atom A—neutrons, B—electron, C—proton, D—nucleus.
