Final answer:
The best description for the increase in pressure when the volume of a plastic bottle decreases is C. uniform, as stated by Boyle's Law where the volume and pressure of a gas are inversely proportional at constant temperature.
Step-by-step explanation:
The increase in pressure when the volume of a plastic bottle decreases can be best described as C. uniform. According to Boyle's Law in physics, for a given mass of an ideal gas at constant temperature, the volume of the gas is inversely proportional to its pressure. This means if you decrease the volume of the gas, such as by squeezing a plastic bottle, the pressure inside will increase uniformly as long as the temperature and the amount of gas remain constant.
The reference to the volume decreasing with both increasing pressure and decreasing temperature pertains to the combined gas laws, where volume and pressure can be related while considering temperature changes. However, because the question seems to focus on a singular action of volume decrease, Boyle's Law is more applicable. Moreover, solids and liquids are hardly compressible, but gases are, which is why a decrease in gas volume inside the bottle results in increased pressure.
When the volume decreases, the gas molecules have less space to move around, so they collide with the walls of the container more frequently, leading to an increase in pressure. This pressure increase would be uniform throughout the container, represented by D. uneven in the multiple-choice options, which would be incorrect in this scenario.