14. In radioactive decays, which of the following statements is incorrect? (A) The energy, momentum, electric charge, and number of nucleons must be conserved. (B) In gamma decay, electromagnetic photons are emitted when a nucleus undergoes a transition from a higher to lower energy. (C) In beta decay, an electron (e- ) or a positron (e+ ) can be emitted by a nucleus. (D) In positron (e+ ) decay, annihilation radiation is generated with different photon energies. (E) The alpha decay is usually observed in the heavy unstable nuclei.