The correct answer is intercontinental ballistic missiles (ICBMs).
ICBMs are capable of carrying nuclear warheads over long distances and can reach their targets in a matter of minutes, giving populations very little time to seek shelter after an alert. The other terms listed, such as "intercontinental ballistic napalm" (ICBNs), "satellite ejected atomic bombs" (SEABs), and "plane dispersed hydrogen bombs" (PDHBs), are not standard or widely recognized classifications of nuclear weapons.