The anode is the negative electrode and so will be donating electrons to assist in this chemical reaction occuring. All reactions accept electrons as reactants. The key issue is the reduction potential Eo (+1.8V). This is greatest for the reaction:
Co3+ + e -> Co2+
Therefore this reaction has the greatest tendency to occur.
Yes explosion is mainly energy
I am pretty sure it is B. If it turns litmus paper red it is acidic. The other 2 make no sense.
I might be wrong tho.
Hope that helped☺️