58. 心臟聽診時第Ⅱ心音之固定性分裂(fixed splitting),最常在下列何種情況可以聽到? (A)僧帽瓣狹窄(mitral stenosis) (B)心室中隔缺損(ventricular septal defect) (C)主動脈瓣狹窄(aortic stenosis) (D)心房中隔缺損(atrial septal defect)