Final answer:
A student nurse should document that a patient is in radiology, notify the charge nurse, and administer the medication when the patient returns, ensuring adherence to nursing standards and patient safety.
Step-by-step explanation:
The appropriate action for a student nurse when a patient is away for radiology during medication administration time would be to document that the patient is in radiology, inform the charge nurse, and administer the medication once the patient returns to the unit. This ensures patient safety and adherence to professional nursing standards. It would not be appropriate to document that the medication was given when it was not, nor would typically an incident report be required for a medication timing adjustment related to diagnostic testing. Communicating with the pharmacy might be necessary if there's concern about the timing or the nature of the medication, but this is not always the first step.