Which of the following is a well-known example of a Radiological Dispersal Device?

A Radiological Dispersal Device (RDD), commonly referred to as a "dirty bomb," is a weapon that combines conventional explosives, such as dynamite, with radioactive material. The primary intent of a dirty bomb is to spread radioactive material over a wide area, creating panic and contamination without necessarily causing significant immediate fatalities through the initial explosion. The psychological effects and the long-term consequences of contamination heighten the impact of such a device.

The other options are not categorized as Radiological Dispersal Devices. A cluster bomb is a type of explosive munition designed to release smaller submunitions over a wide area, typically used in military applications. A nuclear warhead is a highly sophisticated device designed for nuclear detonation, releasing a massive amount of energy through nuclear reactions, rather than dispersing radiological materials. An incendiary bomb is designed to start fires and may burn through materials but does not disperse radioactive substances. Thus, the dirty bomb stands out as the quintessential example of a Radiological Dispersal Device.