$\begin{array}{1 1}(A)\;0.125M\;Na_3PO_4\text{(aq) has the highest osmotic pressure.}\\(B)\;0.500 M\;C_2H_5OH\text{(aq) has the highest osmotic pressure}\\(C)\;\text{They all have the same osmotic pressure.}\\(D)\;0.100M\;Mg_3(PO_4)_2\text{(aq) has the highest osmotic pressure.}\end{array} $