Answer:
Has an opportunity cost 
- Having a "lazy afternoon" VS Working an 8 hour shift VS
- Cooking dinner VS Eating out
- Reading you favorite book VS Catching up with an old friend
Explanation:
Opportunity costs refer to the extra costs or benefits lost associated with choosing one activity or investment over another alternative. In other words, every  activity that you carry out includes the opportunity cost of not doing something else. No matter what we do, we could be doing something else. 
 
        
             
        
        
        
Answer:
B. Full disclosure principle
Explanation:
Full disclosure principle ensures that all relevant financial information is reported
 
        
             
        
        
        
Answer:
The correct answer is letter "C": a result of more efficient resource allocation than would be observed in the absence of trade.
Explanation:
Trade has allowed societies to exchange their products according to their needs. Thanks to trade those goods are distributed accordingly more <em>efficiently </em>since, in isolation, countries would be specialists of certain types of products only which is unlikely to be enough to cover all the individuals' needs in those societies.