The correct answer is B and D . These are the two methods of targeting and applying management profiles to System Manager clients, according to the [System Manager: Getting Started] article. The article explains that:
* Defining the scope: This method allows you to target devices based on their network, tag, or owner.
You can define the scope of a profile from the Systems Manager > Manage > Settings page or from the Systems Manager > Monitor > Overview page.
* Using device tags: This method allows you to target devices based on their attributes, such as OS, model, location, or user. You can use device tags to create dynamic groups of devices that share common characteristics. You can apply device tags from the Systems Manager > Monitor > Devices page or from the Systems Manager > Manage > Tags page.

DHCP Synchronization To prevent a scenario in which an IP address is assigned by the primary via DHCP and then that same address is assigned to another client by the secondary after a failover, the DHCP lease table is synchronized regularly between the primary and secondary over UDP port 3483.
https://documentation.meraki.com/MX/Deployment_Guides/MX_Warm_Spare_-_High_Availability_Pair

Explanation
Quote from referred documentation-Link: Loss and latency will be determined over the configured IP address under Security and SD-WAN > SD-WAN and Traffic Shaping > Uplink Statistics. If no IP is configured, these values will be measured against 8.8.8.8 by default. On the WAN Health page, all the configured IP address statistics can be reviewed by changing the destination under the "Ping Destination" column.
https://documentation.meraki.com/MI/MI_WAN_Health#:~:text=Current%20loss%20and%20latency%20statist

When band steering is enabled on an SSID, APs will stop advertising that SSID in 2.4GHz beacons. Since 2.4 GHz-only clients that rely on a passive scan will not "see" that SSID in beacons, they might not be able to join this SSID unless they do an active scan or have been pre-configured with the SSID name and security settings (for example, a pre-shared key). https://documentation.meraki.com/MR/Radio_Settings
/Band_Steering