Use the graph below to answer the next four questions. A tax on buyers has shifted the demand from $D_1$ to $D_2.$

$4.$ How much is the tax?

A$.$ $$1$ per unit

B$.$ $$2$ per unit

C$.$ $$3$ per unit

D$.$ $$6$ per unit

$5.$ Before the tax, the "price on the price tag" was $$6.$ After the tax, the price on the price tag is $($As we did in class, assume the price on the price tag does not include tax. This is similar to how prices shown at Target are pre$-$tax prices$)$

A$.$ $$4$

B$.$ $$6$

C$.$ $$8$

D$.$ $$9$

$6.$ On a per$-$unit basis, how is the economic burden shared between the buyer and the seller?

A$.$ Buyer pays $$0,$ seller pays $$3$

B$.$ Buyer pays $$1,$ seller pays $$2$

C$.$ Buyer pays $$2.$ seller pays $$1$

D$.$ Buyer pays $$3,$ seller pays $$0$