Answer:
Spain and Austria
a. Spain
b. Austria
c. 5 barrels of oil
d. 0.5 barrels of olives
Step-by-step explanation:
Spain enjoys comparative advantage in the production of olives while Austria enjoys comparative advantage in the production of oil because Spain can produce olives at lower costs than Austria while Austria can produce oil more efficiently than Spain. When these two countries specialize in the production of the product that they enjoy comparative advantage, more goods will be produced in total, and they can exchange their surpluses with the other nation.