In my opinion the interesting point is c). Simply put, humans failed and caused a catastrophe. If you have c), a) and b) don't matter. And we will always have

In my opinion the interesting point is c). Simply put, humans failed and caused a catastrophe. If you have c), a) and b) don't matter. And we will always have c). Humans are currently failing by waging a war around nuclear power plants. How safe those plants are under normal operation doesn't really matter. Humans fail by performing terrorist attacks too. They fail by building nuclear plants that can't handle a tsunami in a tsunami-prone area. Nuclear power provides centuries of opportunity for humans to fail in ways that have immense damage potential. This is clearly a very real risk, and makes nuclear power unsafe. One can still argue for nuclear power, but not by saying it's safe. It simply isn't.