A 66-year-old client presents to the emergency department reporting severe headache and mild nausea for the past 6 hours. Upon assessment, the client's BP is 210/120 mm Hg. The client has a history of hypertension and takes 1.0 mg clonidine twice daily. Which question is most important for the nurse to ask the client next?
A) "Have you taken your prescribed clonidine today?"
B) "Do you have a dry mouth or nasal congestion?"
C) "Are you having chest pain or shortness of breath?"
D) "Did you take any medication for your headache?"