“A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.” - U. S. Constitution, amend. 2.

This meaning of the Second Amendment, quoted here, has often been debated in regard to which issue?

A. the right of police to use weapons

B. the rights of national guard forces

C. the right of states to be free

D. the right of citizens to own firearms