Technician a Says That a Frozen Relay Valve Supplying the Tractor

Multiple Choice

Technician A says that a frozen relay valve supplying the tractor drive axle brakes can cause the brakes not to release.Technician B says that a frozen relay valve can cause service brakes not to apply.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B