Answer:
b. there are no gains from specialization and trade between the two countries.
Step-by-step explanation:
If the two countries are producing goods with the same opportunity cost, then there is no need or advantage gained from the trade of goods between these two countries.
Usually, countries trade with each other if one has a comparative advantage of producing one good over the other trading country. Then in this case is can specialize in making that good and trade the excess to the other country.
However, in the case when two countries are producing apples and oranges. And opportunity cost producing orange for country 1 is one apple and same for country 2
Opportunity cost for Country 1 : 1 Apple = 1 Orange
Opportunity cost for Country 2 : 1 Apple = 1 Orange
Then countries will gain no additional benefit from specializing in one good.