The correct option is A balanced Wheatstone bridge
Meter bridge is an instrument that is used to find the unknown resistance of a coil or any other material. This bridge works under the principle of Wheatstone bridge. We know that the Wheatstone Bridge is used to measure the unknown resistance connected in a circuit. It consists of four resistors of which two resistors are known resistors, one variable resistor and one unknown resistor. It also consists of a galvanometer.