Which of the following is a method of data backup?

The method of data backup referred to in the context of incremental backup is based on the principle of optimizing storage usage and backup time. In an incremental backup, only the data that has changed since the last backup (whether that was a full or another incremental backup) is saved. This approach reduces the amount of data that needs to be copied during each backup session and therefore speeds up the backup process and minimizes storage space requirements.

By only backing up the changes made since the last backup, incremental backups also enable quicker recovery times because the system can restore the most recent full backup and then apply each subsequent incremental backup. This is especially advantageous in environments where data changes frequently, as it provides a more efficient way to maintain up-to-date backups without consuming excessive resources.

While full, continuous, and snapshot backups are all valid methods of data backup, they operate differently. A full backup includes a complete copy of all selected data, while continuous backup involves real-time copies of data as changes occur, and snapshot backup creates a point-in-time representation of data. Each of these methods has its own use cases and advantages, but in the context of the question, incremental backup stands out for its effectiveness in reducing the time and space required for data backups.