Which of the following is a method of backup available in the AWS cloud?

Snapshot backups using Amazon RDS is a method of backup available in the AWS cloud because it allows users to create a point-in-time backup of their database instances easily and efficiently. This type of backup utilizes the underlying storage infrastructure of Amazon RDS, enabling automated and scheduled backups while also allowing for manual snapshots. Snapshots are incremental, meaning only the data that has changed since the last snapshot is saved, which optimizes storage efficiency and reduces costs.

In addition to being a reliable and scalable solution, Amazon RDS snapshots are integrated with other AWS services, allowing users to restore databases quickly if needed. This feature supports disaster recovery scenarios and facilitates seamless database migration or duplication processes.

Other options, such as physical media shipment, virtual local backups, and manual file synchronization, do not represent native methods of backup that are effectively integrated into the AWS infrastructure, which is primarily designed for cloud-based storage and computing solutions.