Final answer:
As the toy car travels up the ramp, its kinetic energy decreases and its potential energy increases due to the height gain and gravity resisting its motion.
Step-by-step explanation:
When a toy car travels up a ramp, its kinetic energy decreases because it is working against the force of gravity which slows down its motion. Conversely, its potential energy increases as it gains height since potential energy is directly related to the object's height above the ground. The correct answer is B) Kinetic energy decreases, potential energy increases. This can also be understood through the conservation of mechanical energy, where the sum of kinetic and potential energy in a system remains constant if only conservative forces are doing work.