By definition, the distance between two points is always positive, so the correct option is D.
Let's say that our plane has rectangular coordinates, so it would be something like a xy-plane.
Each point has 2 coordinates, so we can write:
A = (x₁, y₁)
B = (x₂, y₂)
The distance between the points is given by:
[tex]D = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}[/tex]
As you can see, the distance is defined as positive (indifferent of the coordinates of the points).
So the correct option is D, the distance is always positive.
If you want to learn more about distance, you can read:
https://brainly.com/question/7243416