C5. A supply company offers two non-residential tariffs on a monthly basis: Block Rate Tariff: $1.6 per kWh for the first 2,000 units and $1.3 per kWh for the remaining units. Two-parts Tariff: Maximum Demand Charge is $80 per kVA per month and Energy Charge is $1 per kWh. A shopping mall has a maximum load of 2000kW for all public services. It operates at a monthly load factor of 0.5 and a power factor of 0.9 lagging. Assume the operation of public services for the building is 720 hours per month, determine in steps which tariff the building should select. (6 marks)