A 49-year-old man comes to the physician because of a 2-week history of shortness of breath with exertion. Physical examination shows a brisk carotid upstroke followed by a precipitous downstroke. HR is 84, RR is 16, BP is 160/60. Which of the following is the most likely diagnosis?

Aortic aneurysm

Aortic dissection

Aortic regurgitation

Aortic stenosis

Mitral regurgitation

Mitral stenosis