user interface menus too small on 5k monitor

I recently bought this new monitor

LG 34WK95U-W 34"UltraWide 5K Nano IPS LED Monitor

and use the Adobe CS subscription service, so I have the latest versions.

I can't find a place to adjust the scaling of the user interface for menus and tools.  Searching the forums, it seems it used to be an option. 

Any help?