A current is passed through two electrolytic cells connected in series. The first cell contains aqueous AgNO₃ and deposits 1.08 g of silver metal. The same charge then passes through a second cell containing a solution of a metal ion Mᶻ⁺. If 0.327 g of metal M is deposited and the atomic mass of M is 65.4 g mol⁻¹, what is the value of z, the charge on the metal ion? (Atomic mass: Ag = 107.9 g mol⁻¹)
a) z=3
b) z=4
c) z=2
d) z=1