Which of the following was an inital barrier to european trade in the ming dynasty

There were several barriers of trade with the ming dynasty.
first the Japanese pirates posed a serious threat to sea trade as they kept on attacking merchant ships.
 there was also a great mistrust for foreign powers and trade such that funding of trade and sea safety by the dynasty ceased endangering merchant ships more, which served to isolate China.
 another factor have to do with the rise of the ottoman empires who controlled the Mediterranean,levying huge fees on merchant ships.