What relationship exists between the volume and temperature of a gas?

The correct answer illustrates Charles's Law, which states that the volume of a gas is directly proportional to its temperature when pressure remains constant. This means that as the temperature of a gas increases, its volume also increases. In practical terms, if you heat a gas (thereby raising its temperature), the molecules gain kinetic energy, move more quickly, and push against the walls of their container, resulting in an increase in volume if the container is flexible.

When considering the other statements, they do not accurately reflect the behavior of gases as described by this law. Decreasing volume generally leads to an increase in pressure if the amount of gas is constant, rather than a clear relationship with temperature. It's important to remember that temperature and volume have a reciprocal relationship under constant pressure conditions, meaning they will either both increase or both decrease, which is why the correct answer emphasizes that an increase in volume corresponds to an increase in temperature.