Concept:Household wiring uses parallel connection so each appliance receives the full supply voltage and operates independently.Explanation:In parallel, every appliance is connected directly across the mains, so the voltage across each is the same.In series, the supply voltage would be shared among the appliances. To make all of them work normally, a much higher supply voltage would be required.Therefore, the correct reason is that series connection uses high voltage.Answer:D. series connection uses high voltage