What happens to the pressure of a confined gas when its temperature is increased?

When the temperature of a confined gas is increased, the kinetic energy of the gas molecules also increases. According to the ideal gas law, which relates pressure (P), volume (V), temperature (T), and the amount of gas (n), if the volume of the gas container is held constant and the temperature rises, the pressure must increase to maintain the relationship defined by the law (PV = nRT). This relationship demonstrates that, at a constant volume, an increase in temperature directly results in an increase in pressure because the molecules are moving more vigorously and colliding with the walls of the container more forcefully.

Considering the context of the other options, if the pressure were to decrease or remain the same, we wouldn't see the expected behavior based on the principles of gas laws. Additionally, a scenario in which the gas expands without changing pressure contradicts the fundamental behavior of gases under thermal conditions unless specific conditions such as an external system regulating the pressure are in play. Thus, an increase in temperature in a confined space unequivocally leads to an increase in pressure.