Which of the following is a valid option for a typical command to get its built-in usage information?

-? is not a standard or universally recognized help flag on Linux/Unix systems, though some shells like bash accept it in limited contexts.

-H is not a help flag - it is used in some commands (like find or cp) to control symbolic link behavior.

help is a shell built-in command in bash for getting help on shell built-ins, not a command-line option/flag passed to external commands.

--manual is not a standard option; the correct long option to open a full manual is accessed via the separate man command, not a flag.

The --help flag is the widely adopted GNU long-option convention for displaying a command's built-in usage information. Most Linux commands implement this flag to print a brief synopsis of syntax, options, and usage examples directly to the terminal. It is part of the GNU coding standards and is the most universally recognized option for inline help.