D is the correct answer because OSS supports 3 internal data copies, no human intervention is required to recover the data when anything goes wrong. OSS provides high data reliability and durability by storing multiple replicas of data on different devices in the same region. OSS automatically detects and repairs data errors or failures, and ensures data consistency across all replicas. OSS also supports cross-region replication (CRR) to back up data to another region for disaster recovery12

A, B, and C are incorrect answers because they do not reflect the actual backup technology and policies of OSS.

A is incorrect because OSS does not require manual recovery of data, as it automatically handles data errors or failures.

B is incorrect because OSS provides data protection and backup for customers, and customers do not need to safeguard their own data or use offsite backups.

C is incorrect because OSS does not use RAID0+1 configuration of its underlying physical hard disks, but rather uses a distributed storage system that stores multiple replicas of data on different devices.

References: 1: OSS Overview 2: OSS Backup