C - it's the right cable, but for 99p it'll probably be shite It's a digital connection, so cable quality isn't the issue (passing 0's and 1's is much a sameness) but it's ther termination and quality of the two connectors thats important. But worth 99p if you just wanna test your rig for sure.

I only posted those links to show what you need - I wouldn't pay those prices either. I paid less than a fiver for a brand new 1m digital audio cable, so for a 3m (which I guess is what you need looking at the other cable you linked to) you will be looking to pay £5-£6 for one....