Answer: Corpuscular.
Step-by-step explanation:
There is a theory called the Corpuscular Theory of Light, which says that light is made of small particles called "corpuscles".
But as we know, light has a duality associated to it (it behaves like a wave and like a particle), and here is where one of the largest problems of this theory appears, because it does not explain things like diffraction or interference.
Then the correct option is corpuscular.