Which DVD RW drive I need

Dear readers and specialists

According the serial number I have, I know, it is a iMac 2.8GHz, 24", early 2008. Unfortunately, I don't have access to this device and I need to know which drive out of the four available ones I have to buy.

Serial number: YM8262AAZE4

Thank you for your advice.

Kind regards

Thomas Thaler