Before removing a regulator from an oxygen tank, you should bleed off the pressure by fully opening the flow regulator knob and then turn off the oxygen tank valve completely. This ensures safety and prevents accidental oxygen release during the removal. Thus, the correct option is C.
;
Before removing an oxygen regulator, it is crucial to bleed off the pressure by fully opening the flow regulator knob and then turning off the oxygen tank valve completely. This ensures safety and minimizes the risk of oxygen leaks. Following these procedures prevents accidents during the regulator removal process. ;