Final answer:
An EKG technician should allow a patient who has just exercised to rest for 5 minutes before taking their blood pressure to ensure an accurate reading.
Step-by-step explanation:
When an EKG technician is preparing to obtain a patient's blood pressure reading and the patient has been physically active just prior, the appropriate action is b) Allow the patient to rest for 5 minutes before measuring blood pressure. Exercise increases heart rate and blood pressure temporarily, and it is vital to wait until these measures return to the patient's baseline to ensure an accurate reading. Proceeding with the blood pressure measurement without allowing for this rest period could result in a falsely elevated reading, which is not reflective of the patient's true resting blood pressure levels.