A Student Nurse Is Observing Care Given to a Patient

A student nurse is observing care given to a patient who had cardiothoracic surgery and who now has two chest tubes in the left chest connected by Y tubing. One of the patient's family members asks why the lower chest tube has a great deal of drainage while the upper chest tube has minimal drainage. The best response by the student nurse is:

A) "The upper chest tube is being used to drain air from the chest while the lower one drains blood and fluid."
B) "The upper chest tube is there in case the fluid accumulates near the level of the heart."
C) "The lower chest tube serves as the first drainage system, and if it fills up, the upper tube will begin to drain."
D) "How much drainage is seen in each tube really depends on the type of surgery done. Sometimes the upper one drains more than it does for this case."