In domestic electrical wiring, appliances are typically set up in a parallel connection. This is because a parallel connection allows each device to operate independently of others. For instance, switching off a bulb will not affect a running television because power is equally distributed among all devices. If they were connected in series (option 1), turning off one device might affect the others.

Option 3 suggests a combination of series and parallel connections. This is not typically used in domestic wiring because a single malfunctioning device can impact the entire electrical system.

Option 4 proposes a system where each room is wired in series but connected to other rooms in parallel. This isn`t generally used because a faulty device in one room could cause every device in that room to malfunction, even while devices in other rooms continue to work.

So, the correct answer is option 2, a parallel connection, which provides an independent and more efficient system for domestic wiring.