Two cells undergoing electrolysis are connected in series.

If $x$ g of silver are deposited in cell 1, what volume of oxygen, in dm³ at STP, is given off in cell 2?

A_r(Ag) = 108; Molar volume of an ideal gas at STP = 22.7 dm³ mol⁻¹

A.    $\frac{x}{{108}} \times \frac{1}{4} \times 22.7$

B.    $\frac{x}{{108}} \times 4 \times 22.7$

C.    $\frac{x}{{108}} \times \frac{1}{2} \times 22.7$

D.    $\frac{x}{{108}} \times 2 \times 22.7$

A