Which of the following statement(s) is/are correct? (A) The rest...

- (A) The rest mass of a stable nucleus is less than the sum of the rest masses of its separated nucleons. This is the definition of mass defect, which accounts for the binding energy holding the nucleus together. This energy is released when nucleons combine to form a stable nucleus. - (B) The rest mass of a stable nucleus is greater than the sum of the rest masses of its separated nucleons. This statement is incorrect. If this were true, the nucleus would spontaneously break apart. - (C) In nuclear fusion, energy is released by fusion of two nuclei of medium mass (approx. 100 amu). This statement is incorrect. Nuclear fusion typically involves the fusion of light nuclei (e.g., hydrogen isotopes) to form heavier, more stable nuclei, releasing energy. Fusion of medium-mass nuclei would generally require energy input rather than releasing it, as their binding energy per nucleon is already high. - (D) In nuclear fusion, energy is released by fragmentation of a very heavy nucleus. This describes nuclear fission, not fusion. In fission, a heavy nucleus splits into lighter nuclei, releasing energy.