Osmotic Pressure question

Which of the following aqueous solutions exerts the greatest osmotic pressure?

  1. Na2SO4 10-3M
  2. NaCl 2 x 10-3 mol/L
  3. C6H12O6 0.001M
  4. Na3PO4 0.001 mol/L
  5. KNO3 0.005M

How do we solve this question? I put it into ChatGPT and it used a equation I’ve never came across before.