Ricardo's theory of advantage states that it makes sense for a country to specialize in the production of those goods that it produces most efficiently and then purchase the goods that it produces less efficiently from other countries, even if this means buying goods from other countries that it could produce more efficiently itself.

comparative

Explanation:

A country has comparative advantage in production if it produces at a lower opportunity cost when compared to other countries.

For example, country A produces 10kg of beans and 5kg of rice. Country B produces 5kg of beans and 10kg of rice.  

for country A,  

opportunity cost of producing beans = 5/10 = 0.5

opportunity cost of producing rice = 10/5 = 2

for country B,  

opportunity cost of producing rice = 5/10 = 0.5

opportunity cost of producing beans = 10/5 = 2

Country A has a comparative advantage in the production of beans and country B has a comparative advantage in the production of rice

Country A should specialise in the production of beans and country B should specialise in the production of rice

the answer to this question would be shared investment