Final answer:
When the temperature of a fixed quantity and volume of gas changes, the pressure of the gas changes accordingly, due to the direct relationship between temperature and pressure as described by Amonton's law. So the correct option is c.
Step-by-step explanation:
If the temperature of a fixed quantity and volume of gas changes, the pressure also changes. This is based on Amonton's law, which states that for a given amount of gas at a constant volume, the pressure of the gas is directly proportional to its temperature. If the temperature increases, the pressure increases due to the increased force and frequency of molecular collisions. Conversely, if the temperature decreases, the pressure within the gas also decreases. This relationship between temperature and pressure at a constant volume can be derived from the Kinetic Molecular Theory (KMT) and is quantitatively explained by the gas laws.