According to the relation $\Delta_rG = -nFE_{cell}$, the Gibbs free energy change ($\Delta_rG$) depends on the number of moles of electrons transferred ($n$). This is because $E_{cell}$ is an intensive property (independent of the amount of substance), while $\Delta_rG$ is an extensive thermodynamic property (dependent on the amount of substance, represented by $n$). Thus, Reason (R) is true and correctly explains Assertion (A).