When Governments Operate Landfills as Enterprise Funds, Which of the Following

When governments operate landfills as enterprise funds, which of the following is correct?

A) GASB requires that certain post-closure costs be estimated and accrued during the period the landfills receive solid waste.
B) GASB requires that a portion of future estimated costs be charged as an expense and liability of the landfill using units-of-production method as waste is accepted.
C) The purpose of recording post-closure expenses and liabilities is to match the estimated costs with the revenues during the period of time the waste is accepted.
D) All of the above are correct