Final answer:
Nurse Chris should check Derek's blood glucose level to determine if hypoglycemia is causing his symptoms and act accordingly.
Step-by-step explanation:
Nurse Chris is responding to the situation in which Derek is tearful, irritable, and not acting like himself. Additionally, Derek is exhibiting diaphoresis, a term used for excessive sweating, which can be a symptom of various medical conditions, including hypoglycemia (low blood sugar). Considering these observations, the appropriate action for Nurse Chris to take would be a) Check Derek's blood glucose level. This initial step is crucial for determining whether Derek's symptoms are due to fluctuating blood sugar levels, which is common in diabetic patients. If Derek's blood glucose is low, immediate interventions, such as providing a source of glucose, would be necessary to prevent further complications.