Suppose demand is downward sloping and supply is upward sloping. Which of the following statements is most correct?

Opening a market to trade increases total surplus, thereby improving the welfare of both producers and consumers.

A tax will always produce a deadweight loss but a price ceiling will not always produce a deadweight loss.

A decrease in supply always makes sellers worse off.

The government can always increase tax revenue by increasing the per unit tax.

dont answer by pen paper