<prompt>  A 60-year-old man with a 20-year smoking history is brought to the physician by his daughter because of altered behavior over the past week. She says that her fathers personality has changed. He has had a productive cough over the past month, for which he is taking over-the-counter medications. He is not a drug addict, diabetetic or hypertensive. Physical examination shows multiple bruises on the skin and hyper-pigmented spots on the buccal mucosa and the back of his neck. His blood pressure is 16090 mmHg, and pulse is 70mm. Laboratory studies show random blood sugar of 224 mgdL, serum sodium of 140 mEqL, serum potassium of 2.0 mEqL, and serum bicarbonate of 27 mEqL. Which of the following tests is most likely to be abnormal in this patient?CT chestMRl brainPlasma metanephrine IevelsRenal Doppler 