A. Line & Plane

B. Plane & Line segment

C. Point & Line segment

D. Point & Line

*The answer is option D. Point & Line.*

A ray is defined as a part of a line that starts at a particular point (called the endpoint) and extends infinitely in one direction. The two undefined terms used to define a ray are:

**Endpoint**: The starting point of the ray.**Direction**: The direction in which the ray extends infinitely.

Together, these two undefined terms specify the geometric object known as a ray.

In geometry, a ray is a part of a line that begins at a specific point (endpoint) and extends infinitely in one direction. A ray is named based on its endpoint, and any other point on the ray is identified by its position in relation to the endpoint.

The endpoint of a ray is also sometimes referred to as the origin, and the direction in which the ray extends is referred to as the ray’s direction. The direction of a ray can be identified by an arrow placed over the ray to indicate its direction.

One important property of a ray is that it has only one endpoint. This means that a ray cannot be defined by two distinct points. In contrast, a line segment has two endpoints and is defined by those two distinct points.

Rays are used in many areas of mathematics and physics, particularly in geometry and optics. In geometry, rays are used to define angles, and they are also used to define line segments, polygons, and other geometric objects. In optics, rays are used to model the path of light as it travels through a medium, such as air or water.