The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.
In this question, the light ray passes from air to water, an optically denser medium.
Imagine drawing a line to representing the boundary between two mediums. Now imagine drawing a line perpendicular to that boundary line marking where the light ray intersects the boundary line. This second line is called the normal. Whenever a light ray passes into a denser medium with a nonzero angle of incidence, the ray will bend towards the normal, making the angle of refraction smaller than the angle of incidence.
Choice A
