The correct answer is: B. Live wire and the earth wire
The main switch of the house is a double pole switch, which means that it disconnects both the live wire and the neutral wire. This is done to ensure that there is no current flowing through the circuit when the switch is off.
The live wire is the wire that carries the current from the power source to the appliance. The neutral wire is the wire that carries the current back to the power source. The earth wire is a safety wire that is connected to the ground. It is designed to provide a safe path for current to flow in the event of a fault.
When the main switch is turned off, it breaks the connection between the live wire and the neutral wire. This means that there is no current flowing through the circuit and the appliance cannot be turned on.
The earth wire is not connected to the main switch. This is because the earth wire is only used in the event of a fault. If there is a fault, the current will flow through the earth wire and to the ground. This will help to prevent the appliance from becoming live and causing a shock.
I hope this explanation is helpful. Please let me know if you have any other questions.