This question tests the understanding of Faraday's laws of electrolysis. The key concept from the textbook is that the amount of electricity required depends on the stoichiometry of the electrode reaction. For Ca²⁺ + 2e⁻ → Ca, one mole of Ca requires 2 moles of electrons (2F). For Al³⁺ + 3e⁻ → Al, one mole of Al requires 3 moles of electrons (3F). The molar masses (Ca = 40 g/mol, Al = 27 g/mol) are used to convert given masses to moles, then multiplied by the electrons required per mole.