A set of points which extend infinitely in both directions is called ______
A. Line
B. Plane
C. Line segment
D. Point

Hint: In this question we have to find which type of geometrical figure can extend infinitely in both directions which means that it does not have any end points. So we will first try to understand the definition of line, line segment, point and plane. From this we will be able to choose the correct option.

Complete answer:
First , let us understand the definition of the line segment. A line segment has two endpoints. It contains all the points of the line between them. We can measure the length of the line segment.
While we know that a line is an infinitely thin and long collection of points extending in two opposite directions. We cannot measure the length of a line but we can measure the line segment.
The diagrammatic representation of line is as follows:

As we know, a plan is a flat surface that extends infinitely in all directions. While a point is the most fundamental element of geometry. We can represent a point by dot and named by a capital letter.
Therefore from the above definition, we can see that a line is made of a group of points which can extend infinitely in both directions.

Therefore, the correct option is A

Note: We should be careful and remember the definition of line and line segment. It should be noted that a line has no end or starting point while a line segment has both starting point and end point. We can draw a line segment without any points, as below:

In the above figure, we have a line “m” .