The Mossbauer effect (answer (A)), the Casimir effect (answer (B)), and the photoelectric effect (answer (C)) describe completely unrelated phenomenon. The Mossbauer effect describes the absorption or emission of a photon by a nucleus in a solid. The Casimir effect describes the attraction between the two plates of a parallel plate capacitor due to the vacuum polarization that occurs in quantum electrodynamics. The photoelectric effect describes the process of photons transferring their energy to electrons in a metal.
All elementary particle interactions can be classified as electromagnetic, weak, or strong interactions. A neutrino is emitted in interaction in this problem, and neutrinoes only interact weakly, so this is an example of a weak interaction. Therefore, answer (D) is correct.