Final answer:
Objective data refers to observable and measurable information about a patient's condition. In this case, the irregular radial pulse of 50 beats per minute is an example of objective data.
Step-by-step explanation:
The human response that is an example of objective data identified by the nurse would be option 1: Irregular radial pulse of 50 beats per minute. This is because a pulse rate is a vital sign that can be directly observed and measured by a clinician. In contrast, options 2 through 4 (pain scale rating, shortness of breath, and dizziness) describe subjective data, which are symptoms that are reported by the patient and cannot be directly measured in a clinical setting.