You can export best what you produce in great amount and Southeast Asia is know for producing great amounts of rice -so rice is the correct answer!
In fact, they would more likely import wheat and corn, as they probably don't produce enough even for their own needs.
They changed the two-field crop rotation to a four-field crop rotation which allowed the farmer to grow food more consistently and the rotation from a root vegetable to a grain in the fields also allowed the cattle to be fed and the excess grain to be sold
They're separated by the South China Sea.
the answer is A. mexico city because there is over 10 dots in that area