In its 2010 McDonald v. Chicago decision about the Second Amendment, the Supreme Court ruled that A. states must enact "duty to retreat" laws.
B. the Second Amendment does not entitle law-abiding citizens to own a firearm.
C. the Second Amendment is incorporated under the Fourteenth Amendment.
D. only the national government can pass laws regulating firearms.
E. state and local governments cannot pass laws regulating firearms.
