For Landfills Accounted for as Enterprise Funds, a Portion of the Estimated

For landfills accounted for as enterprise funds, a portion of the estimated cost of closure of solid waste landfills should be charged as an expense and a liability of the landfill operation each year on a:

A) Actual cost method.
B) Units-of-production method.
C) Estimated cost method.
D) None of the above.