【单选题】

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.