A client manages rental property income and expenditures on behalf of numerous landlords. Landlords own the properties, which are then rented out to the tenants. The client needs to track by the landlord, by the property, and by tenants.

Which one method of monitoring income and expenditure would be most appropriate, especially if the client needs to re-charge expenses for costs incurred to maintain properties?

A. Sub-customers

B. Projects

C. Locations

D. Classes