Drag the missing word into place This is the law of square : price increases, quantity demanded decreases; price decreases, quantity demanded increases. demand surplus market

#Explanation#The question is asking to fill in the blank with the appropriate economic principle that describes the relationship between price and quantity demanded. The principle that states when the price of a good increases, the quantity demanded decreases and vice versa is known as the "Law of Demand". This law is a fundamental concept in economics that illustrates the relationship between the price of a good and the quantity of that good that consumers are willing and able to purchase. It is based on the basic economic principle of negative or inverse relationship between price and demand.#Answer#The missing word is "Demand". The completed sentence should read: "This is the law of Demand: price increases, quantity demanded decreases; price decreases, quantity demanded increases."