How do they come up with $84,000.00 being the answer? 

Joe has a DP-3 policy with $80,000 Coverage A.  A tornado blows the house down, totally destroying it.  A $2,000 storage shed is also destroyed.  It takes the insured four (4) months to rebuild the houses, and he usually rents it for $500.00 per month.  There is about $2,000 of furniture (ACV) that is destroyed.  Ignoring any deductible, how much will the policy pay? 

How is $84,000 the answer?  There is no coverage B for the storage shed, there is no coverage C for the furniture and no coverage D for Fair Market Rental.    Please show me how $84,000.00 is the answer.