A Concentration Cell Is Built Using Two Au/Au³⁺ Half-Cells

A concentration cell is built using two Au/Au³⁺ half-cells. What is the cell potential E _cell for this concentration cell given the following two half-cell Au³⁺ ion concentrations:
[Au³⁺]_dil = 7.0×10 ^{- 4} M [Au³⁺]_conc = 2.5×10 ^{- 2} M

A) - 0.092 V
B) - 0.031 V
C) 0.031 V
D) 0.092 V
E) 0.276 V