After the required date for operator certification, who may operate the municipal waste combustion unit?

After the required date for full or provisional certifications, you must not operate your municipal waste combustion unit unless one of four employees is on duty: (a) A fully certified chief facility operator. (b) A provisionally certified chief facility operator who is scheduled to take the full certification exam. (c) A fully certified shift supervisor. (d) A provisionally certified shift supervisor who is scheduled to take the full certification exam.