The incorrect information is:
The spot marked “maximum gravitational potential energy” should be on the lowest point of the roller coaster, at the far left side on the bottom.
This statement is wrong because gravitational potential energy is at its maximum when the roller coaster is at its highest point. Conversely, at the lowest point of the roller coaster, the potential energy is at a minimum, while kinetic energy is at its maximum due to the speed of the roller coaster at that point. Therefore, the spot marked "maximum gravitational potential energy" should be at the highest point of the roller coaster, not at the lowest point.