where is the potential energy of the roller coaster the lowest?
(A)
(B)
(C)
(D)

I think it should be D. Because the potential energy of a roller coaster is at its lowest point or is the least at the bottom of the lowest point in the roller coaster. It is at its greatest at the top of the highest point of the roller coaster. Hope this helps! =^-^=
Answer:
D
Explanation:
The potential energy of an object depends on its mass, the acceleration of gravity and the height above the surface of the earth to which it is located.
Potential Energy (U)
[tex]U=mgh[/tex]
where m is the mass, g is the acceleration of gravity and h is the height.
Since the mass is the same at all points and g is also the same, the point with the lowest potential energy should be the point that is at the lowest height, wich is point D.