(Advanced Analysis) the Equations for the Demand and Supply Curves

(Advanced analysis) The equations for the demand and supply curves for a particular product are P = 10 − 0.4Q and P = 2 + 0.4Q, where P is price and Q is quantity expressed in units of 100.After an excise tax is imposed on the product, the supply equation is P = 3 + 0.4Q.The excise tax on each unit of the product

A) is $1.
B) is $2.
C) is $3.
D) cannot be determined with the information given.