正解:B
Disaster recovery is the aspect of cloud design that enables a customer to continue doing business after a major data center incident. Disaster recovery is the process of restoring and resuming the normal operations of IT systems and services after a disaster, such as a natural calamity, a cyberattack, a power outage, or a human error. Disaster recovery involves creating and storing backup copies of critical data and workloads in a secondary location or multiple locations, which are known as disaster recovery sites. A disaster recovery site can be a physical data center or a cloud- based platform. Disaster recovery in cloud computing offers many advantages, such as:
Cost-effectiveness: Cloud disaster recovery eliminates the need to invest in and maintain expensive hardware, software, and facilities for the secondary site. Cloud disaster recovery also allows customers to pay only for the resources they use, and to scale up or down as needed.
Reliability: Cloud disaster recovery ensures that the backup data and workloads are always available and accessible from any location and device. Cloud disaster recovery also leverages the security, performance, and redundancy features of the cloud provider to protect the data and workloads from corruption, loss, or theft.
Flexibility: Cloud disaster recovery enables customers to choose from different cloud service models and deployment options, such as public, private, hybrid, or multicloud, depending on their business needs and preferences. Cloud disaster recovery also allows customers to customize and automate their recovery plans and policies, such as recovery point objective (RPO) and recovery time objective (RTO).