Which disk to choose when doing a clean install of MacOS Catalina? Right now I am doing a clean install of Catalina. I have erased the Macintosh HD and the Macintosh HD -Data. When I tried to install the OS it gave me these two choices again. I couldn’t find anything on apple’s website on this choice of drives. I chose now the Macintosh HD because it is defined as the system drive but I am not sure. I would be happy if you provide some information or a reference about this.
What worked for me was erasing the parent volume of these partitions as "Macintosh HD", leaving one partition.

Another option, as per lx08's comment, is to delete "Macintosh HD - Data" and erase "Macintosh HD".