Concept:Nuclear energy is the energy released from changes in an atomic nucleus.
Explanation:The question asks which process generates nuclear energy and who proposed the relevant equation.
Two main processes release nuclear energy: nuclear fission (splitting a heavy nucleus) and nuclear fusion (combining light nuclei).
Both are governed by Einstein’s mass‑energy equivalence principle, expressed by the equation
E=mc2.
Therefore, among the options, nuclear fission is directly associated with Einstein’s equation.
Rutherford discovered the nucleus, Bohr contributed to atomic structure, and Heisenberg worked on quantum mechanics — none proposed the energy equation for fission.
Answer:Option A: nuclear fission and its expression was proposed by Einstein.