Which of the following scenarios best illustrates unit elastic demand?

A 15% increase in the price of salt leads to no change in quantity demanded.

A 10% increase in the price of gasoline leads to a 5% decrease in quantity demanded.

A 5% decrease in the price of luxury cars leads to a 10% increase in quantity demanded.

A 20% decrease in the price of clothing leads to a 20% increase in quantity demanded.