A Nurse Administers an Antihypertensive Medication to a Patient at the Scheduled

A nurse administers an antihypertensive medication to a patient at the scheduled time of 0900.The nursing assistant then reports to the nurse that the patient's blood pressure was low when it was taken at 0830.The nursing assistant states she was busy and had not had a chance to tell the nurse yet.The patient begins to complain of feeling dizzy and light-headed.The blood pressure is re-checked and it has dropped even lower.The nurse first made an error in what phase of the nursing process?

A) Assessment
B) Diagnosis
C) Planning
D) Evaluation