What is comparative advantage? when country A exports its goods to country B in exchange for other goods
when country A imports all the goods that country B produces in exchange for certain goods it cannot produce
when country A faces a smaller opportunity cost in the production of certain goods as compared to country B
when country A can produce all of its goods in a more cost-effective manner than country B

when country A faces a smaller opportunity cost in the production of certain goods as compared to country B

Explanation:

I'm gonna go with this one because comparative advantage is when a country produces a lot of a particular item but doesn't consume that much because of the amount they are able to produce.  They also are able to produce this item at a good opportunity price.  

let me know if this helps enough.

answer; analytical,creative and practical;

sounds good to me mate!