Answer:
The endpoints of the line segment lie on each other
Step-by-step explanation
To understand the question, follow the practical steps below
1. Take a sheet of plane paper
2. Label the edges of the top of the paper A and B
3. Fold the paper in such a way that edge A lies on B.
You'll notice the following;
1. The top of the paper lies in itself; hence, we can say that the line segment lies on itself
2. You have a new line at the centre of the paper. The point at the top of this center line is the midpoint of the line segment
3. The edges that lie on each other translates to the endpoints lying on each other.
Number (3) above is the required observation and the right answer.