The command which lists databases managed by the server is . . . . . . . .

Answer: Option B

This question asks you about the command used to view the databases in your MySQL server.

Let's break down the options:
* Option A: mysqld is the actual MySQL server, not a command to list databases.
* Option B: mysqlshow is the correct command to display a list of databases. It's specifically designed for this purpose.
* Option C: mysqllist doesn't exist as a standard MySQL command.
* Option D: mysqldb also doesn't exist as a standard MySQL command.

Therefore, the answer is Option B: mysqlshow.