Which Statement Made by an EMT Demonstrates an Understanding of Chest

Which statement made by an EMT demonstrates an understanding of chest trauma?

A) "Open chest injuries are more serious than closed chest injuries, because air and bacteria can enter the chest through the open wound."
B) "In general, an open chest injury caused by blunt trauma is more life threatening than a closed one due to increased potential for blood loss."
C) "Closed chest injuries are caused by blunt trauma, and can be just as serious as open chest injuries."
D) "Closed chest injuries are caused by penetrating trauma and cause more life-threatening injuries than do open chest injuries."