Which Is TRUE About the Pleural Sac

Multiple Choice

Which is TRUE about the pleural sac?

A) It is continuous with the atmosphere and protects the lungs from infection.
B) It is a closed sac surrounding each lung that contains only a tiny volume of lubricating fluid.
C) It is a closed sac surrounding each lung and contains a large volume of surfactant.
D) It is a closed,air-filled space surrounding both lungs that has a negative pressure compared to atmospheric pressure.
E) It is bounded by pleural membranes that are very thin,which allows for abundant gas exchange.