The correct answer is A. lsblk because it is specifically designed to display detailed information about block devices such as hard drives, SSDs, partitions, and their mount points in a structured, hierarchical format. The lsblk (list block devices) command provides a clear overview of how storage devices are organized, including relationships between disks and their partitions.
When executed, lsblk shows important details such as device names (e.g., sda, sdb), sizes, types (disk or partition), and mount points. This makes it extremely useful for system administrators when managing storage, troubleshooting disk issues, or verifying newly attached devices.
Option B (mount) is incorrect because it is used to mount filesystems, not to display a comprehensive list of all block devices.
Option C (df) is incorrect because it shows disk space usage of mounted filesystems, not detailed device-level information.
Option D (fdisk) is partially related but incorrect in this context. While fdisk can be used to view and manage partition tables, it is more interactive and not as convenient for simply displaying a structured overview of all block devices.
From a Linux+ system management perspective, lsblk is an essential tool for storage administration. It allows administrators to quickly assess disk layouts, identify mounted and unmounted devices, and verify configurations. Its readability and efficiency make it a preferred command for everyday disk management and troubleshooting tasks in Linux environments.
