Which of the Following Political and Administrative Changes Did Diocletian

Which of the following political and administrative changes did Diocletian not make?

A) Ending the principate by adopting the title of "lord" (dominus) and having himself worshipped as a living god
B) Returning all civil power to the Senate, which would choose the consuls
C) Dividing the empire between four rulers: two augusti who would each choose a caesar
D) Concentrating most of the army at inland bases, to be quickly moved to any threatened part of the border