Q. A 27-year-old woman comes to the clinic because of shortness of breath (dyspnea). The patient mentions that she hardly tolerates exercise due to dyspnea and palpitations. The patient has no significant past medical history and takes no regular medications apart from oral contraceptive pills. Vital signs are normal, and her ECG shows no abnormalities. The patient's echocardiography shows a mitral valve leaflet bulging into the left atrium. Which of the following is expected on cardiac auscultation of this patient?