Which situation is an example of comparative advantage in an international market?

country a decides to grow extra potatoes so they have more to export, while country b does not.
factories in country a can produce the same number of tablets as factories in country b, or the factories in country a could be used to build more laptops than the factories in country b.
country a invests in a new technology while country b chooses to invest in education.
farmland in country a can produce 100 units of rice per acre, while country b can only produce 70 units of rice using the same amount of workers and farmland.

Factories in Country A can produce the same number of tablets as factories in Country B, or the factories in Country A could be used to build more laptops than the factories in Country B is an example of comparative advantage in an international market.

Explanation:

The comparative advantage of manufacturing a good or service is smaller than that of other nations. Opportunity cost compensation measures.  

A country with a comparative advantage pays off. The benefits of buying are higher than the drawbacks.  

Perhaps the nation isn't the best producer. But for other countries, good or service costs are low.

For Example, Call centers in India. U.S. businesses buy the service because the location of the call center in America is cheaper. Call centers in India are no different than U.S. call centers. Their employees don't always talk very clearly in English. Nonetheless, they offer the service inexpensive enough to make the deal worthwhile.

the investment was $14,174.196

explanation:

a lump sum means that the father of the example made one deposit and leave it be.

we need to know the value of a capital that generated at 4.05% per year during 28 years the sum of $48,613.24

now clearing the formula to solve for capital we got:

and we reach the answer investment = $14,174.20