Comprehensive and Detailed Explanation (HCIA–Cloud Computing aligned):
In the HCIA–Cloud Computing syllabus, Linux command-line operations are part of the Operating System Basics domain. Viewing file contents is one of the most common Linux administration tasks.
The less (A) command is used to view file contents page by page. It supports forward and backward scrolling and searching, making it suitable for viewing large files. HCIA materials often recommend less as a preferred file-viewing tool.
The more (B) command is an earlier paging command that displays file contents one screen at a time. Although it has fewer features than less, it is still a valid file-viewing command.
The cat (D) command is used to display the entire content of a file directly to standard output. It is commonly used for viewing small files or concatenating files.
The vim (C) command is primarily a text editor, not a file-viewing command. While it can open and display files, its main purpose is editing rather than viewing, which is how HCIA differentiates it.
Therefore, the correct answers are A, B, and D.
