What Evidence Does Polsby Cite for His Claim That Gun

What evidence does Polsby cite for his claim that gun control laws don't work?

A) Efforts to curtail the supply of firearms inflict collateral damage on freedom and privacy interests.
B) Gun control laws impact law-abiding citizens negatively but criminals will always have access to guns via illicit markets.
C) Gun control laws amount to an unreasonable tax on firearms-a tax both on time and money.
D) All of the above