After Intubation of a Cardiac Arrest Victim, You Observe a Slow

After intubation of a cardiac arrest victim, you observe a slow but steady rise in the expired CO₂ levels as measured by a bedside capnometer. Which of the following best explains this observation?

A) return of spontaneous circulation
B) abnormally high $\dot { V } / \dot { Q }$
C) placement of the endotracheal tube in the esophagus
D) failure of the cuff to properly seal the airway