In the gasoline market example, the price of $1.40 per gallon sets quantity demanded and quantity supplied equal at 600 million gallons. If the price instead sat above $1.40, at $1.80, what happens to quantity demanded and quantity supplied compared with their values at $1.40?

1. Move along both curves from the $1.40 equilibrium up to $1.80. 2. Along the demand curve, a higher price lowers quantity demanded, from 600 down to 500 million gallons. 3. Along the supply curve, a higher price raises quantity supplied, from 600 up to 680 million gallons. 4. So quantity demanded falls while quantity supplied rises, producing an excess supply of 180 million gallons. 5. Option C ignores the law of demand, and option D ignores the law of supply. _Source: OpenStax Principles of Macroeconomics for AP Courses (CC BY 4.0), Ch 3 "Demand and Supply", section 3.1 | Demand, Supply, and Equilibrium in Markets for Goods and Services_