What does "perfectly inelastic demand" imply?

"Perfectly inelastic demand" refers to a situation where the quantity demanded of a good remains constant regardless of any changes in its price. This means that consumers will continue to buy the same amount of the product whether the price goes up or down. A classic example of perfectly inelastic demand is life-saving medications; no matter the price, patients who need these medications will purchase them since their health depends on it.

This concept is crucial for understanding consumer behavior in markets, especially for essential goods or services where substitutes are not available. In such cases, the demand curve is represented as a vertical line on a graph, indicating that price changes do not influence the quantity demanded at all.

In contrast, the other options describe different scenarios regarding demand sensitivity and consumer preferences, which do not align with the characteristics of perfectly inelastic demand.