86 45歲男性身體檢查發現二尖瓣脫垂(Mitral valve prolapse)及閉鎖不全(Mitral insufficiency),其瓣 膜最可能的病理變化是:(A) Fibrosis with commissural fusion(B) Fibrinoid necrosis(C) Myxomatous degeneration(D) Calcification