In the diagram shown, all the four electrical components are correctly matched.
a) Plug key or switch is a device for making and breaking the connection in an electric circuit.
b) A wire joint is a joint by which two wires are united.
c) Electric bulb is an electric device with a wire filament heated to a high temperature, by passing an electric current through it, until it glows with visible light.
d) An electrical cell is a device that is used to generate electricity, or one that is used to make chemical reactions possible by applying electricity.