Which of the file information given in options is useful to recover from a crash?

Backup information is the only metadata that directly enables recovery of lost or corrupted files after a system crash. File Type, File Name, and Last usage are descriptive metadata that help identify or organize files, but they do not contain the actual file content or recovery data needed to restore a crashed system. Backups store redundant copies of critical data, allowing restoration to a known good state.

Step-by-step Derivation:
In system crash recovery scenarios, the goal is to restore lost or corrupted data. Analyzing each option: (A) Backup information—contains actual file data snapshots, enabling complete recovery; (B) File Type—only identifies format (e.g., .txt, .exe), does not aid recovery; (C) File Name—only identifies the file label, does not aid recovery; (D) Last usage—timestamps indicate when accessed, but provide no recovery capability. Only backup information contains the redundant data necessary for restoration.