The purpose of a Cache Repository when adding a file share in Veeam Backup & Replication is D: To store temporary metadata and track all objects that have changed. When Veeam Backup & Replication backs up data from file shares, it uses the Cache Repository to store metadata related to the files and directories on the share. This metadata includes information about file versions, change logs, and the structure of the file share, which is essential for efficient backup operations, incremental backups, and restore operations. The Cache Repository plays a crucial role in tracking changes between backup jobs, enabling Veeam to perform quick incremental backups by only processing the data that has changed since the last backup, thereby optimizing backup performance and reducing network and storage load.