In humans, if the diaphragm is pushed upward, there is a decrease in chest volume. This decrease is followed by:

When the diaphragm is pushed upward, it reduces the volume of the chest cavity. According to Boyle's law, which states that pressure and volume are inversely related in a closed system, a decrease in volume results in an increase in pressure within that system. As the chest volume decreases due to the diaphragm moving upward, the pressure inside the chest cavity rises.

This increased pressure inside the chest cavity exceeds the atmospheric pressure, leading to the movement of air out of the lungs, resulting in exhalation. The body's respiratory mechanics facilitate this process, where the diaphragm's upward movement during active exhalation aids in expelling air from the lungs.

Understanding the relationship between pressure and volume in the thoracic cavity is crucial in respiratory physiology, as it defines how ventilation occurs, illustrating the mechanics that govern inhalation and exhalation. Thus, the correct choice denotes that the increase in pressure in the chest cavity following a decrease in volume corresponds with the process of exhalation.