Which Is the Balanced Half Reaction in Basic Solution for the Reaction

Which is the balanced half reaction in basic solution for the reaction below?
Cr(OH) ₄^- $\rightarrow$ CrO₄^2-

A) 3 e^- + Cr(OH) ₄^- + 2 OH^- $\rightarrow$ Cr(OH) ₄^- + 2 H₂O
B) 4 OH^- + Cr(OH) ₄^- $\rightarrow$ CrO₄^2- + 3e^- + 4 H₂O
C) 2 OH^- + Cr(OH) ₄^- $\rightarrow$ CrO₄^2- + 6 e^- + 3 H₂O
D) Cr(OH) ₄^- $\rightarrow$ CrO₄^2- + 4 H₂O + 2 e^-