What is a shortage?

A shortage refers to a situation in which the quantity of a good or service demanded exceeds the quantity supplied at a given price. This imbalance typically occurs when the price of a good is set too low, causing consumers to want more of it than producers are willing to provide. In this context, the correct choice identifies that a shortage is characterized by a lack of goods needed in sufficient amounts, resulting in consumers being unable to purchase as much of the product as they desire.

The other options present scenarios that do not align with the concept of a shortage. An excess of supply over demand reflects the opposite situation, known as a surplus, where goods are available in greater quantities than consumers want. A state where goods are plentiful suggests that supply meets or exceeds demand, which contradicts the definition of a shortage. Lastly, achieving a balance of supply and demand indicates a market equilibrium, where shortages do not exist because the quantity supplied equals the quantity demanded.