For a closed circuit Daniell cell, which of the following plots is the accurate one at a given temperature?

Standard Cell Potential ($$E^\circ_{\text{cell}}$$) is a thermodynamic constant for a specific redox couple (like $$Zn/Cu^{2+}$$) at a fixed temperature ($$298\text{ K}$$) and standard conditions ($$1\text{ M}$$ concentration, $$1\text{ bar}$$ pressure).

                                         Daniell cell

Plot B (The Horizontal Line): Shows $$E^\circ_{\text{cell}}$$ remaining constant over time. This is the accurate plot. Since $$E^\circ_{\text{cell}}$$ is a constant for the Daniell cell