While Discussing the Catalyst Efficiency Monitor: Technician a Says If

Multiple Choice

While discussing the catalyst efficiency monitor: Technician A says if a fault occurs in the catalyst monitor system on three drive cycles, the MIL is illuminated. Technician B says if the catalytic converter is not reducing emissions properly, the voltage frequency increases on the upstream HO2S. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B