ARe you sure it's the HD? Does it do it from the moment you boot up the PC.
Yes I am sure, I checked to make sure the source of the sound was coming from the hard drive, and it occurs like once every 4 seconds after the computer has fully booted.
If your hard drive is clicking then it is an indicator that some of the internal components are not working correctly. To be safe I would backup everything you want to keep off that drive immediately.
That my friend is the sound of impending failure. Its going to fail, whether its today or next week. You should back up your stuff and RMA the drive immediately.
Be very gentle with the drive this often happens from the drive being dropped in shipping (which obviously you can't prevent).
Sorry that you are facing some issues with your WD drive.
I would also say that you need to back up the data stored on it as soon as possible.
After that, you can attach it with different cables to a different SATA port. In case the issue persists, you can just contact the retailer or WD's Support and RMA the drive.