After initiating B-CPAP in an infant at 6 cm H2O, the therapist notices that, although "bubbling" is present, the pressure in the manometer fluctuates between 2 and 5 cm H2O. What may have caused this situation?

A. The FiO2 was not increased sufficiently.
B. A problem with the interface has likely developed.
C. The flow through the CPAP system is too low.
D. The CPAP level was not raised enough.