Complete the Balancing of the Following Half-Reaction, Taking Place in Basic

Complete the balancing of the following half-reaction, taking place in basic media. How many hydroxide ions are needed to balance the half-reaction? Cr(OH) ₄(aq) $\rarr$ CrO₄²(aq) Hint: Remember the coefficients when balancing half-reactions and look carefully at the oxidation numbers.

A) 1 hydroxide ion, on the left side
B) 3 hydroxide ions, on the right side
C) 3 hydroxide ions, on the left side
D) 4 hydroxide ions, on the left side
E) 4 hydroxide ions, on the right side