Huawei divides DR into data-level, application-level, and service-level protection according to recovery requirements and investment.
For data-level DR, the remote site primarily protects copies of production data. Huawei explicitly states that a data-level DR center cannot prevent service interruption when a disaster occurs; it operates essentially as a backup center from which data can later be restored. Therefore, C is correct and D is false.
For application-level DR, the backup site contains the same application system as the production site and data is synchronized between the sites using synchronous or asynchronous mechanisms. This allows applications to be restarted at the DR site within the defined RTO, making B correct.
Service-level DR is the most comprehensive level. Huawei defines it as a complete DR environment covering IT technologies and infrastructure as well as non-IT resources such as offices and telecommunications. A redundant workplace may therefore be required if the normal business site becomes unavailable.
Hence, A, B, and C are correct.
Study Guide Topics: Data Protection Solution → DR Basics → DR Levels → Data-Level → Application-Level → Service-Level DR.