Which of the Following Highlights What May Be the Greatest

Which of the following highlights what may be the greatest threat from RDDs?

A) A terrorist group threatening a weaker government with an RDD could gain access to more dangerous resources.
B) The radiation after an RDD lasts a long time and is often described as nothing short of "severe."
C) The explosion itself will probably cause more damage than anything else.
D) RDDs pose little threat since the explosion is not that big and everyone knows that the radiation from them is minimal.