What Do Economists Mean When They Speak of Price as a Rationing

What do economists mean when they speak of price as a rationing mechanism?

A) That all goods produced will be sold.
B) Consumers get the products they want at prices they can afford.
C) That shortages of goods in the market price will disappear as a result of price rising which results in the quantity demanded increasing.
D) That shortages of goods in the market price will disappear as a result of price rising which results in the quantity demanded decreasing