69. A 32-year-old woman returns to her physician for follow-up of hypertension that has been poorly controlled in spite of numerous antihypertensive medications. It is decided to evaluate the patient for possible "secondary"hypertension. Which of the following is a well-known cause of secondarv hvpertension?
A. Ethnicity B.Obesity C. Renal artery stenosis
D. Smoking E. Stress