During the "golden age" of china, leaders thought of themselves as isolated, yet which of the following? able to be self sufficient as a country able to teach other countries economic and political leadership better than any other country on the planet protected by their military

The correct answer is "Better than any other country on the planet". The Chinese empire practiced the Isolationism during different dynasties, particularly during Ming dynasty, with Hongwu Emperor proposing the policy to ban all maritime shipping in 1371. Chinese leaders practiced this policy to avoid enemies to enter to their territory and because they believed they were superior to any other country and China could be self-sufficient.