GENERAL KNOWLEDGE

Detailed explanation-1: -Quarks combine to create composite particles called hadrons, and the most stable of which are neutrons and protons, the components of atomic nuclei. Thus, the nuclear particles which are assumed to hold the nucleons together are Mesons. Therefore, option (D) is the correct answer.

Detailed explanation-2: -Nuclear particles responsible for holding all nucleons together are mesons. To account for the binding forces between like particles such as proton and proton or neutron and neutron, Kemmer suggested the existence of a neutral meson (0).

Detailed explanation-3: -Nuclear forces (also known as nuclear interactions or strong forces) are the forces that act between two or more nucleons. They bind protons and neutrons (“nucleons”) into atomic nuclei. The nuclear force is about 10 millions times stronger than the chemical binding that holds atoms together in molecules.

Detailed explanation-4: -Protons and neutrons are best known in their role as nucleons, i.e., as the components of atomic nuclei, but they also exist as free particles.