What Half-Reaction Occurs at the Cathode During the Electrolysis of Molten

Multiple Choice

What half-reaction occurs at the cathode during the electrolysis of molten potassium bromide?

A) K(s) $\to$ K⁺( $\ell$ ) + e^-
B) Br₂( $\ell$ ) + 2e^- $\to$ 2Br^-( $\ell$ )
C) 2Br^-( $\ell$ ) $\to$ Br₂( $\ell$ ) + 2e^-
D) K⁺( $\ell$ ) + e^- $\to$ K(s)
E) 2H₂O( $\ell$ ) + 2e^- $\to$ H₂(g) + 2OH^-(( $\ell$ )