For extraction of sodium from `NaC1`, the electrolytic mixture `Nac1+Na_(3)A1F_(6) +Cac1_(2)` is used. During extractions process, only sodium is deposited in cathpode but `K` and `Ca` do not because
A. Na is more reactive than K and Ca
B. Na is les reactive than K and Ca
C. NaCl is less stable than `Na_(3)AlF_(6) and CaCl_(2)`
D. the discharge potential of `Na^(+)` is less than that of `K^(+) and Ca^(2+)` ions
