What principle does this demand curve demonstrate

In economics, the demand curve is the graph depicting the relationship between the price of a certain commodity and the amount of it that consumers are willing and able to purchase at any given price. It is a graphic representation of a market demand schedule.

The correct answer is that the demand curve demostrate that people want what the product or service is providing.

Explanation:

When the demand curve goes high the supply may be low and the price goes high. Economic is an simbiotic process.

b.provides a written record of the transaction