The number of pairs of the solutions having the same value of the osmotic pressure from the following is ______.
(Assume \( 100\% \) ionization)
A. \( 0.50 \, \text{M} \, \text{C}_2\text{H}_5\text{OH} (\text{aq}) \) and \( 0.25 \, \text{M} \, \text{KBr} (\text{aq}) \).
B. \( 0.100 \, \text{M} \, \text{K}_4[\text{Fe}(\text{CN})_6](\text{aq}) \) and \( 0.100 \, \text{M} \, \text{FeSO}_4 \, (\text{NH}_4)_2 \text{SO}_4 (\text{aq}) \).
C. \( 0.05 \, \text{M} \, \text{K}_4[\text{Fe}(\text{CN})_6](\text{aq}) \) and \( 0.25 \, \text{M} \, \text{NaCl} (\text{aq}) \).
D. \( 0.15 \, \text{M} \, \text{NaCl} (\text{aq}) \) and \( 0.1 \, \text{M} \, \text{BaCl}_2 (\text{aq}) \).
E. \( 0.02 \, \text{M} \, \text{KCl} \cdot \text{MgCl}_2 \cdot 6\text{H}_2\text{O} (\text{aq}) \) and \( 0.05 \, \text{M} \, \text{KCl} (\text{aq}) \).
