Final answer:
The CPCT should ask the patient about their breakfast intake.
Step-by-step explanation:
The CPCT should take action C) Ask the patient about their breakfast intake.
During a Glucose Tolerance Test (GTT), the patient is typically required to fast for 12 to 24 hours prior to the test. If the CPCT notices an empty breakfast plate on the patient's bedside table, it indicates that the patient has not followed the fasting instructions. In this case, it is important to ask the patient about their breakfast intake to determine if the test can still proceed or if it needs to be rescheduled.