※This sample exam is different from those that appear in the actual OSS-DB Exam.
In psql, several meta commands that begin with (backslash, in many Japanese environments) are prepared, and you can check the table list, structure, etc. And you can display help for the command.
To display how to use various commands of SQL, enter \h or \help followed by the SQL command name.
There is no meta command called man, howto, so an error occurs. When describe is executed, it is regarded as a meta command called des and a list of external servers is displayed.
Therefore, the correct answer is D.