Suppose There Is Currently a Tax of $100 Per Ticket

Suppose there is currently a tax of $100 per ticket on airline tickets. Sellers of airline tickets are required to pay the tax to the government. If the tax is reduced from $100 per ticket to $80 per ticket, then the

A) demand curve will shift upward by $20, and the price paid by buyers will decrease by less than $20.
B) demand curve will shift upward by $20, and the price paid by buyers will decrease by $20.
C) supply curve will shift downward by $20, and the effective price received by sellers will increase by less than $20.
D) supply curve will shift downward by $20, and the effective price received by sellers will increase by $20.