Technician a Says If You Remove the PCV Valve from the Valve

Technician A says if you remove the PCV valve from the valve cover and plug the end with your finger, the idle will increase if the valve is good. Technician B says that when you block the flow to the PCV valve, it will richen the air-fuel mixture. Which technician is correct?

A) Technician A
B) Technician B
C) Both technicians
D) Neither technician