A diode is forward biased when the anode is connected to the positive terminal and the cathode to the negative terminal of a voltage source. This allows current to flow easily. The correct symbol shows the triangle (anode) pointing towards the negative side, with a voltage source applied such that the positive terminal connects to the anode.

The correct connection is the third image, where the positive terminal is connected to the anode (P-side) and the negative terminal to the cathode (N-side).

Final Answer: Third option