Final answer:
Ryan's blood pressure of 80/45 and pulse rate of 48 warrants immediate intervention by the Emergency Department Registered Nurse.
Step-by-step explanation:
The assessment data that warrants immediate intervention by the Emergency Department Registered Nurse is option B) Ryan's blood pressure of 80/45 and pulse rate of 48.
A blood pressure of 80/45 is considered extremely low and indicates hypotension, which can be life-threatening. Combined with a pulse rate of 48, it suggests poor perfusion and compromised cardiac output. This requires immediate medical attention to stabilize the patient's condition.