Researchers at MIT have shown that plasmon excitations associated with two-dimensional materials can be used to enhance and control light-matter interactions to allow typically forbidden interactions to occur. Indicate, by name or number, all of the following three statements that are true of forbidden transitions: 1) Transitions where the orbital angular momentum changes by more than 1 unit are forbidden 2) Forbidden mechanisms do not obey conservation of angular momentum 3) Metastable states decay by emitting more than one photon