Concept:A tax raises price, so the fall in consumption depends on the price elasticity of demand.
Explanation:When a good has price elastic demand, consumers respond strongly to a price rise.
A tax increases the price of the good.
If demand is elastic, the quantity demanded falls substantially.
This large fall in quantity demanded discourages consumption effectively.
If demand were price inelastic, the quantity demanded would fall only slightly, so consumption would not be discouraged much.
Answer:C. price elastic