Replacing an electric cord

Good day, i have two cords for the wall unit however i need to connect the one with four bronze metal plugs to go on the dryer. My problem is that i nee to know exaclty how to connect it cuase the dryer has only three places for the wires. The cord has four wires. i know that one is for ground but where does it go?

American A/C & Appliance :wink: