If your GPU supports your monitor's Resolutions and Frequencies then either AMD driver is good.
But the WHQL has been verified to be tested and compatible with Windows 10. Generally this is a stable Driver whereas the Optional hasn't yet been tested but has improvements or fixes that the WHQL may not have but may be buggy in certain respects.
So depending on why you are updating the AMD Driver. If are just updating for the sake of updating then I would use the WHQL driver. But if you are updating for a specific issue you are having and the Optional might fix that then I would install the Optional AMD Driver.