Which of the following blood pressure measurements indicates the lowest pressure within the arteries?

Diastolic pressure represents the lowest pressure within the arteries during the cardiac cycle. It occurs when the heart is in a relaxed state, specifically when the ventricles are filling with blood. During this phase, the heart is not actively pumping, which allows the arterial pressure to drop to its lowest point.

In contrast, systolic pressure is the highest pressure recorded in the arteries when the heart contracts and pumps blood out to the body. Pulmonary pressure refers to the pressure within the pulmonary arteries, which is related to the function of the lungs, and central venous pressure measures the pressure in the thoracic vena cava, near the right atrium of the heart. None of these pressures indicate the lowest arterial pressure, making diastolic pressure the correct choice.