Why did the ming dynasty restrict trade with europe

Although Jorge Álvares was the first to reach the island of Lintin in the Pearl River delta in May 1513, it was Rafael Perestrello, a cousin of Christopher Columbus, who became the first European explorer to disembark on the south coast of China and to trade with Guangzhou in 1516. In 1517, the Portuguese launched a large commercial expedition in Guangzhou and sent a delegation on behalf of Manuel I of Portugal to the court of Emperor Zhengde, relations quickly degraded after death of the emperor when the ambassadors of Malacca (in present-day Malaysia) accused the Portuguese of having dethroned their king.In 1521 and 1522, Chinese naval forces expelled the Portuguese ships and the first rear-loading culverines arrived in China.

austria

hugary

yugoslavia

czechoslovakia

answer: the ocean

explanation: if you map out 30 n and 40 n latitude, you will get the ocean