The true statements about natural disasters from the options provided are:
b they are defined by a potential for a geologic, hydrologic, atmospheric, or biological event to occur
c they affect different regions in different ways
a is false because laws, infrastructure, and communication can help mitigate the impacts of natural disasters.
d is false because natural disasters can occur all over the world, not just in the Ring of Fire.
So, both b and c are true.