What are drawn on light rays to show the direction in which light travels?
A. RAYS
B. ARROWS
C. LINES
D. LINE SEGMENTS

Hint: Propagation of light refers to the process in which an electromagnetic wave transfers its energy from one point to another point. Light rays are not an exact description of the light rather they show the direction in which they travel. Arrows are used to show the direction in which light travels.

Complete step by step answer:
We are given to find what is used to show the direction in which light travels.
Light is an electromagnetic radiation within the portion of the electromagnetic spectrum that can be detected by the human eye.
A light ray is a straight line or curved line that is perpendicular to the light's wave fronts. Light rays in homogeneous media are straight.
Light rays when passed through a media bend at a certain angle which is called incident angle and gets reflected back at some other angle which is called reflected angle.
Light starts at a single point and continues to infinite distance when there are no obstacles in its path.
So, light rays are represented using Arrows, because arrows have a starting and extending till infinite from another direction.
The correct option is Option B, Arrows.

Note:Incident rays, reflected rays, refracted rays are the most common types of light rays. In reflection, light rays falling on the plane return to the same medium and the waves bounce off the surface. On the other side, in refraction, the waves pass through the surface, change their speed and direction and pass through another medium. Do not confuse reflected rays with refracted rays.