Answer:
D. The electrochemical reaction of the battery must be reversible.
Step-by-step explanation:
The batteries are based on the production of an electric flux given by a redox reaction. This reaction is spontaneous and is thermodynamically favored.
Thus, when the reactants to the reaction are finished, the flow of current stops and ends. Therefore, when current is administered from another source, the reaction changes its direction and reagents that were previously consumed begin to occur. Therefore the condition for it to be rechargeable is that the reaction can go forward or backward, that is, it is reversible.