Which of these is an example of objective data?

Objective data refers to information that is measurable and observable, typically gathered through systematic observation or scientific measurements. In this context, the blood pressure reading exemplifies objective data because it is a quantifiable value obtained using a sphygmomanometer, providing concrete evidence about the patient's cardiovascular health.

In contrast, the other options involve subjective data, which relies on personal interpretations or feelings of the patient. The patient's report of pain and feelings of nausea are dependent on individual experiences and perceptions, making them subjective. Similarly, the patient's mood, while it can be observed by caregivers, is still interpreted through the patient's expression and communication, and is therefore not as definitive or measurable as a blood pressure reading. This distinction between objective and subjective data is crucial for healthcare providers in order to accurately assess patient conditions, make informed decisions, and provide appropriate care.