Determine the osmolarity of a solution containing 0.450 M of C ₃H₈O₃ and 0.15 M of Na ₂SO₄.

• A. 0.23 osmol/L
• B. 0.45 osmol/L
• C. 0.68 osmol/L
• D. 0.90 osmol/L

Answer: (D)