A client with a pneumothorax receives a chest tube attached to a Pleur-evac. The nurse notices that the fluid of the second chamber of the Pleur-evac isn’t bubbling. Which nursing assumption would be most invalid（）
A. The tubing from the client to the chamber is blocked.
B. There is a leak somewhere in the tubing system.
C. The client’s affected lung has reexpanded.
D. The tubing needs to be cleared of fluid.