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

B