Which is wrong about facial vein?
A.
The triangulation area from nasion to bilateral corners of the mouth is named as dangerous triangle.
B.
Facial vein has no venous valve.
C.
In situation of facial infection, extrusion is suggested to conduct.
D.
Facial vein begins from angular vein.
E.
Facial vein communicates with pterygoid venous plexus via deep facial vein.