What Was the Significance of the Mainland Kingdoms and Island

What was the significance of the mainland kingdoms and island states of southeast Asia that surrounded the three great manufacturing zones of the Asian sea trading network?

A) These regions were virtually the sole consumers of goods made in the manufacturing regions.
B) These regions fed raw materials, precious metals and forest products, into the trading network.
C) These regions provided the military defense for the manufacturing regions.
D) These regions had no relationship to the three main manufacturing zones of the Asian sea trading network.