Answer:
B. Technician B only
Explanation:
The PCV valve (PCV: Positive Crankcase Ventilation Valve) allows the passage of oil and hydrocarbon vapors generated in the crankcase to the intake manifold and then to the combustion chambers where they are burned, thus eliminating the high pressure generated in the inside of the engine and reducing the emanation of polluting products towards the environment.
When the pressure of the oil and gasoline vapors in the crankcase is high then the PCV valve opens allowing the passage to the intake manifold to be burned.