The Figure Given Below Shows the Demand and Supply Curves

The figure given below shows the demand and supply curves of automobiles.Figure 13.3
In the figure,
D: Demand curve of automobiles
S: Supply of automobiles prior to the tax
S+t: Supply of automobiles after the tax

-Which of the following is an example of the command approach to regulation?

A) The sale of tradable permits to emit sulfur dioxide in the Chicago Mercantile Exchange
B) Enforcing private property rights and private ownership of elephants in Africa
C) Zoning in many areas that restricts the types of buildings that can be built
D) The government providing subsidies for public education
E) A Pigouvian tax