This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Medicine
A 18-year-old man notices occasional lightheadedness when standing up quickly. He also has difficulty playing sports because of easy fatigue and SOB. Examination shows normal heart sounds, but a loud systolic ejection murmur at the right sternal border. The murmur decreases with elevating the legs and increases in the standing position. Your clinical diagnosis is hypertrophic cardiomyopathy (HOCM).For the above patients, select the characteristic arterial pulse finding. 
Select and explain. 
A. pulsus tardus, B. pulsus paradoxus, C. hyperkinetic pulse, D. bisferiens pulse
D: bisferiens pulse
Answer: D: bisferiens pulse 
Explanation: The bisferiens pulse, two systolic peaks, occurs in HOCM and aortic regurgitation. In aortic regurgitation, the bisferiens pulse can occur both in the presence or absence of aortic stenosis.