The correct answer is: B. Stimulated emission.
Stimulated emission is a process in which an atom or molecule in an excited state is stimulated by a photon of the same frequency to emit a second photon of the same frequency. This process is the basis of laser operation.
Blackbody radiation is the electromagnetic radiation emitted by a black body, an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. The radiation is characterized by a continuous spectrum that peaks at a wavelength that depends on the temperature of the black body.
Planck’s radiation law is a law that describes the spectral distribution of electromagnetic radiation emitted by a black body. The law was first proposed by Max Planck in 1900, and it is one of the most important laws in quantum mechanics.
Einstein oscillation is a process in which an atom or molecule in an excited state oscillates between two energy levels. The oscillation is caused by the absorption and emission of photons.
Stimulated emission is the only process that can amplify light. Blackbody radiation, Planck’s radiation law, and Einstein oscillation are all processes that describe the emission of light, but they do not amplify light.