The resettling of irradiated particles released into the atmosphere after a nuclear explosion is called fallout.
Answer: Option A
Step-by-step explanation:
Fallout literally is the coming down of radioactive particles released from a nuclear explosion. The particles of the exterior of the exploded weapon, radioactive material used inside the nuclear weapon, and the disturbed and raised soil particles from where the weapon was dropped mix into the atmosphere after the explosion. These particles gradually come down due to the action of gravity. The process of coming down of these particles is called 'fallout'.