Context: Mackenzie is sitting on a roller coaster cart as it reaches the bottom of a big loop. Earth's gravity is pulling down on Mackenzie with a force of 600N. The seat of the cart is pushing up on Mackenzie with a force of 1,200N.
Assume all other forces on Mackenzie are balanced. Which statement describes the forces on Mackenzie?
A. The forces are unbalanced, so there is a net force on Mackenzie.
B. The forces are balanced, so there is no net force on Mackenzie.
Identify the correct choice from the options below and respond with the letter of the correct option.

A