Concept:Building insurance is a common expense shared by departments using a fair physical base.
Explanation:Insurance on the building is an expense for the entire building, not for one department alone.
In departmental accounts, such building-related costs are apportioned based on the floor space occupied by each department.
This is because insurance premiums usually depend on the size and risk of the whole building, and floor space fairly measures each department’s share of that risk.
Other bases like purchase cost, building value, or number of offices are not used for insurance apportionment.
Answer:A. floor space occupied by the department