After selecting your mirror, the stage 2 menu appears for the first time:
=> 1. Configure local disk(s)
2. Select package repository
3. Select package groups
4. Install packages
5. Post install configuration
6. Installation and configuration complete
7. Drop to shell
[1] >
If you don't know for certain that your local disks are configured (partitioned and formatted) correctly and prepared for cAos to be installed, select the default, option one.