The correct answer is: D. Elasticity of Demand
Elasticity of demand is a measure of how responsive the quantity demanded of a good is to a change in its price. It is calculated as the percentage change in quantity demanded divided by the percentage change in price.
A demand curve is said to be elastic if the quantity demanded changes by a large percentage in response to a small percentage change in price. A demand curve is said to be inelastic if the quantity demanded changes by a small percentage in response to a large percentage change in price.
The law of demand states that, all other things being equal, the quantity demanded of a good will decrease as the price of the good increases. The law of supply states that, all other things being equal, the quantity supplied of a good will increase as the price of the good increases.
Equilibrium price is the price at which the quantity demanded of a good is equal to the quantity supplied of the good.
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