The thermal energy in a heat engine is used to move a piston. Which best describes why this is possible?
A. The increase in thermal energy results in an increase in pressure
B. The decrease in thermal energy results in an increase in pressure.
C. The increase in thermal energy results in a decrease in pressure.
D. The decrease in thermal energy results in a decrease in pressure.

The increase in thermal energy results in an increase in pressure.

Explanation:

The increase in entropy is directly related to the increase in temperature. So the thermal energy in heat engine increases the temperature of that surrounding.Higher temperature means the kinetic energy of particles is also higher, their vibration is increasing. So it increases the pressure (ideal gas law).In this way the increment in the thermal energy in heat engine moves piston by increasing the pressure.