e) the product records a window on behalf of each customer, and the customer can report an incident like this to both Meta and legal authorities including such a recording. Strangers who sexually proposition kids get removed from the platform and may face legal consequences. The virtual space is like a public physical space where anyone else can report your crimes.
If this were a physical space (e.g. a park?) and your pre-teen kids were able to hang out there, the analogs to a-c would all sound crazy. Being carded upon entry to a park, or knowing that everything you say there will be monitored by a central authority would both be really weird. Saying "parents must watch their kids" seems less practical in a VR space where you can't necessarily just keep line-of-sight to your kids.