Which of the following statements about blood pressure measurement is true?

For accurate blood pressure measurement, it's essential that the patient is at rest for a sufficient period, typically around five minutes, before the measurement is taken. This resting period allows the cardiovascular system to stabilize and helps to ensure that the reading reflects the patient's true resting blood pressure rather than any transient changes caused by activity or stress. Measuring blood pressure when the patient is relaxed and seated contributes to obtaining a more consistent and reliable reading.

Other options entail practices that could lead to inaccurate measurements. For instance, measuring blood pressure while the patient is standing could result in a lower reading due to potential fluctuations in blood pressure when standing versus sitting or lying down. Placing the cuff on the forearm instead of the upper arm can lead to inconsistent readings since the forearm may not provide the same results as the upper arm where the brachial artery, used for standard measurements, is located. Additionally, measuring over clothing can obscure the reading by preventing the cuff from fitting tightly against the skin, which is necessary for an accurate assessment. Thus, the importance of having the patient rest for five minutes is pivotal for achieving a valid and representative blood pressure measurement.