5. 正常情況下，有關靜脈直接回流的路徑敘述，何者正確？ (A) 頭靜脈( cephalic vein )匯入內頸靜脈(internal jugular vein ) (B) 左側睪丸靜脈(left testicular vein )匯入下腔靜脈(inferior vena cava ) (C) 大隱靜脈( great saphenous vein )匯入膕靜脈( popliteal vein ) (D) 奇靜脈( azygos vein )匯入上腔靜脈(superior vena cava )