Why Did Augustus Not Create and Codify in Law a Formal

Why did Augustus not create and codify in law a formal mechanism by which all future emperors could be chosen?

A) Augustus died before he could designate a successor.
B) Since the Roman Empire was not formally a monarchy, no successor could automatically inherit the previous emperor's power without the Senate's approval.
C) He feared that establishing a hereditary monarchy would incur divine wrath.
D) He did not wish to limit the powers of the institutions from the republic that were still functioning, including the assemblies and the Senate.