When the cell concentrates potassium within, against the natural tendency of matter, it is performing

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.

i might be wrong but i think its a. let me know if i’m right and have a good rest of your day!