The answer is: D
Chandragupta Maurya's empire was considered one of the most efficient and organized empires the world had ever seen. This was due in part to the way the empire was organized and run.
One the ways he found to organize such a vast empire was through a highly organized centralized bureaucracy, this means that at the center of it all would be him as king and from him and from there he could delegate his administration through different departments to take care of a wide array of tasks.