The answer is B) First-come, First-Served
It is commonly used when there are problems price ceilings and works as a system of 'waiting lines'
This is also known as the the Queuing System and it works on the system of simply discriminating anyone based on location, age, race etc.
This works best in non-priced rationing system and ensures the development of a system that can work for everyone.
Queuing systems have been used various times in the history especially in socialist/communist states in Eastern Europe and Russia.
For a time, during World War II it was also implemented in Great Britain.
In America's history, there is only one noticeable period of rationing and that only occurred on the supply of Oil, during the 70s oil crises.
