Explanation:

- A coil of wire in an electric room heater is designed to resist electric current and produce heat. It is commonly known as the Element.

- Option 4: Element - This is the correct answer. It refers to the heating element that converts electrical energy into heat.

- Option 1: Cell - A cell is an electrochemical cell that stores energy and provides power to a circuit, commonly found in batteries.

- Option 2: Fuse - A fuse is a safety device that interrupts the flow of current if it exceeds a certain level, preventing damage to the circuit.

- Option 3: Switch - This device is used to open or close an electrical circuit, controlling the flow of current.