Which explains why U.S. leaders are eager to get North Korea to sign the Nuclear Nonproliferation Treaty?
a. North Korea has targeted U.S. allies with threats of nuclear attacks and ultimate destruction.
b. North Korea has launched a nuclear attack against the United States in the past.
c. North Korea has demonstrated that it has access to more nuclear weapons than any other country.
d. North Korea has the ability to fire a nuclear weapon that could reach U.S. territory.

U.S. leaders are eager to get North Korea to sign the Nuclear Nonproliferation Treaty because a) North Korea has targeted U.S. allies with threats of nuclear attacks and ultimate destruction. This includes the United States and South Korea, where the United States has been its' longtime enemy for the past few decades and there has been humongous tension between North and South Korea. Since North Korea is one of the most private and secretive countries in the world, no one knows exactly how much nuclear power it has.