Based on the typical behavior of a roller coaster and the principles of conservation of energy, the most accurate statement among the options provided would be:
Both potential and kinetic energy change, but total energy does not change.
This statement aligns with the understanding that as a roller coaster moves along the track, potential energy (due to its height) and kinetic energy (due to its speed) transform into one another, but the total mechanical energy remains constant, assuming negligible losses due to friction or air resistance.