The known forces of nature can be divided into four classes, such as gravity, electromagnetism, weak nuclear force and strong nuclear force. With reference to them, which one of the following statements is not correct?

• A. gravity is the strongest of all
• B. Electromagnetism only acts on particles with electric charge
• C. Weak nuclear force is the cause of disintegration
• D. Strong nuclear force holds protons and neutrons in the nucleus of an atom