Technician a Says That When Working on a Refrigerant

Multiple Choice

Technician A says that when working on a refrigerant system you should work in a well-ventilated area.Technician B says to determine the type of refrigerant used in a system,a refrigerant identifier should be used prior to servicing the vehicles refrigerant system.Who is correct?

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