The component labeled "A", as shown in the illustration, would be identified as the __________. Illustration GS-0175

Correct Answer: Option D — oil/water interface level sensing probe

The oil/water interface level sensing probe (A) monitors the thickness of the oil layer within the separator vessel. This critical component ensures that oil is automatically discharged to the waste oil tank when the interface reaches a predetermined level, preventing oil carryover into the processed water discharge stream.