Answer: The correct answer is reflection.
Step-by-step explanation:
Reflection: It is the phenomenon in which the light rays bounce back from the surface without getting absorb or transmit.
In the given problem, The image of the colorful trees can be seen in the water of the lake. This is due to the reflection. The light rays will be incident on the colorful trees and then these rays reflected back on the surface of the water. Then these rays converge to form the mirror image of the trees.
Therefore, in the given question, the image causes due to the reflection.