The correct option is C only (b)
Components connected in series are connected along a single path, so the same current flows through all of the components. The current through each of the components is the same, and the voltage across the circuit is the sum of the voltages across each component. In a series circuit, every device must function for the circuit to be complete. One bulb burning out in a series circuit breaks the circuit. A circuit composed solely of components connected in series is known as a series circuit.
Components connected in parallel are connected so the same voltage is applied to each component. In a parallel circuit, the voltage across each of the components is the same, and the total current is the sum of the currents through each component. In parallel circuits, each light has its own circuit, so all but one light could be burned out, and the last one will still function. A circuit composed solely of components connected in parallel is known as a parallel circuit.
In this case, the figure (a) represents a serial connection and the figure (b) represents a parallel connection.
Therefore, a parallel connection is preferred in a household circuit.
The main advantages of the parallel system are that the supply can be tapped at any convenient point in the house; moreover each appliance is operated by a separate fuse. If the fuse blows off, only that appliance is to be checked. This system involves less wiring and is cheaper to set up.