Prior to obtaining an MEP value with a pressure manometer, the respiratory therapist notes the needle is pointing at a positive pressure of -4 cmH2O prior to the maneuver. During the MEP maneuver, the needle reaches 32 cmH2O. The therapist should

a) Document the findings as normal
b) Repeat the maneuver with a new manometer
c) Check for leaks in the system
d) Report the results to the physician