Why is that answer correct?

Reflection 4. In Argentina they can produce 1 unit of beef in 4 labor hours and 1 unit of wheat in 8 labor hours. In Brazil they can produce 1 unit of beef in 2 labor hours and 1 unit of wheat in 6 labor hours. Using the principle of comparative advantage A. Argentina should produce both beef and wheat B. Brazil should produce both beef and wheat C. Brazil should produce wheat and Argentina should produce beef D. Argentina should produce wheat and Brazil should produce beef