Which of the following phenomena proved that the photon has particle nature?

Photoelectric effect

Phenomena that supports the particle nature of photons is the photoelectric effect.

Albert Einstein's explanation of the photoelectric effect in 1905 proposed that light consists of discrete packets of energy called photons. The photoelectric effect occurs when light, usually in the form of photons, strikes a material and ejects electrons from it.

The observed behavior, such as the immediate emission of electrons once a certain threshold frequency is reached, strongly supports the idea of photons as particles.