12. 造成病人心臟傳導受阻之隔緣肉柱(septomarginal trabecul( A )會與右心室的哪一個構造混合？ (A)前乳頭肌(anterior papillary muscle) (B)隔乳頭肌(septal papillary muscle) (C)後乳頭肌(posterior papillary muscle) (D)三尖瓣(tricuspid valve)