Comprehensive and Detailed in-depth Step-by-Step Explanation:To answer this question, we need to understand the roles of OSPF routers:
* Area Border Router (ABR):
* An ABR is a router that connects multiple OSPF areas. It has at least one interface in the backbone area (Area 0) and one or more interfaces in other OSPF areas.
* The ABR performs summarization between areas and propagates routing information between them.
* Backup Router (BR):
* The term "BR" does not exist in OSPF terminology. Instead, OSPF uses the term "Backup Designated Router (BDR)." The BDR is a backup to the Designated Router (DR) in a specific OSPF broadcast or NBMA (Non-Broadcast Multi-Access) network. The BDR takes over the DR's responsibilities if the DR fails.
Key Clarification:
* An ABR is related to the hierarchical structure of OSPF areas and is not tied to the DR/BDR election process.
* A router can function as an ABR without ever being a DR or BDR, as these are separate roles.
Therefore, the statement that an ABR must also be a BR is FALSE.
References:
* Huawei HCIA-Datacom Study Guide, Chapter on "OSPF Fundamentals".
* RFC 2328 - OSPF Version 2.
* Huawei OSPF Configuration Guide.

Comprehensive and Detailed Step-by-Step Explanation:
* Analysis of VRRP Configuration:
* Option A (Preemption): Correct. The output explicitly states that preemption is enabled.
* Option C (Authentication): Correct. Authentication is enabled using MD5.
* Option D (Group ID): Correct. The VRRP group ID is explicitly stated as 1.
* False Statement:
* Option B (mVRRP Group): The output does not indicate this is an mVRRP (Multicast VRRP) group. This feature must be explicitly configured and is not enabled by default.
References:
* HCIA-Datacom Study Guide, Chapter: VRRP Configuration Details
* Huawei VRRP Command Reference

The preference of routing protocols determines the selection order of routes when a router receives multiple routes to the same destination from different routing protocols. For instance, OSPF has a higher preference over RIP, so OSPF routes will be selected first. Huawei routing preferences confirm this behavior .

The Local-Preference attribute is used within an AS to influence outbound traffic paths. The default value is
100, and it is a well-known discretionary attribute, meaning it is not mandatory and does not travel across AS boundaries .