The system variable 'system_time_zone' can be reset at runtime.

This question is about the 'system_time_zone' variable in MySQL, which tells us the time zone being used by the database.

The question asks if we can change this variable while the MySQL server is running (runtime).

To answer this, we need to understand that 'system_time_zone' is a global variable that is set when the server starts.

While MySQL allows us to change some system variables during runtime, the 'system_time_zone' variable is usually not one of them.

Therefore, the correct answer is Option B: False.