Correct Answer - Option 3 : Both a & b
An antenna is an electrical device that converts electrical signals to electromagnetic waves and vice versa, i.e. Electromagnetic waves to Electrical signals as well.
At the transmitter: The electric current supplied to the antenna makes the electrons vibrate. These vibrations of electrons generate electromagnetic radiation which travels as radio waves.
At the receiver: When the waves arrive at the receiver antenna, they make electrons vibrate inside it. This produces an electric current that recreates the original signal.
