Narcissus gazes down into a pool of water and sees his face. This is a result of
Seeing an image at the interface between two mediums is a result of reflection.
a) refraction, incorrect, Refraction is the bending of a wave when entering a medium in which its speed is different.
b) dispersion, incorrect, Dispersion refers to a medium in which the velocity of light depends on its frequency. One common example is a dispersive prism which splits multi-hued light into a rainbow due to differences in refraction as the light passes through the prism geometry.
c) diffraction, incorrect, Diffraction refers to the effects of a wave encountering a slit.
d) reflection, correct, The water surface functions as a plane mirror.