Answer: The correct option is (A).
Explanation:
Reflection: It is the phenomenon in which the light rays bounce back from the surface without getting transmit.
Refraction: It is the phenomenon in which light ray gets bend or change its speed while travelling from one medium to the another due to change in the speed of light.
In the given problem, Serena draws a diagram to compare when the rays hit a boundary and are either reflected or refracted.
In the given diagram, the part X represents the reflection and the part Z represents the refraction. The part Y in the diagram represents similarities between reflection and refraction.
Therefore, the labels belong in the area marked X,Y and Z in the given diagram represents as follows;
A. X: ray bounces off a boundary and maintains constant speed
Y: ray changes direction
Z: ray passes through a boundary and changes speed
