All of the above are correct answers
Loess, which can be carried by wind over long distances.
If you only want to balance nuclear reactions, then you should know that number of nucleons are conserved before and after nuclear reaction. Also, charge is conserved as well.
Other things which are conserved in a nuclear reaction are:
Conservation of:
1. Parity
2. Spin
3. angular momentum(vector sum of intrinsic spin and orbital angular momentum)
4. linear momentum
5. Isotopic spin
6. Energy
I believe it would be the first option. It forms iron oxide (rust) when exposed to moisture and air.