If you already started with B then stick with B and ignore what the panel says. If the panel is pre-marked with A color coding and you want to do B then swap green and orange compared to what the chart says.

Easiest fix is to replace the WiFi extender in the basement with another router. The tenants would connect to that one (whether physically or via WiFi) and the network provided by that router will be mostly separate from your own. If none of them are tech-y this should work fine but otherwise still allows them to connect into your network if they know what they’re doing and make an effort to do so. Think of it like a cheap lock—keeps honest people honest but someone with sufficient motivation can still break in.

There are more secure ways but they would involve replacing pretty much all of your networking gear with more capable equipment as you will need VLANs and a competent firewall.