The coagulating power of an electrolyte for arsenious sulphide decrease in order

• A

  $\mathrm{Na}^{+}\gt\mathrm{Al}^{3+}\gt\mathrm{Ba}^{2+}$
• B

  $\mathrm{PO}_4^{3-}\gt\mathrm{SO}_4^{2-}\gt\mathrm{Cl}^{-}$
• C

  $\mathrm{Cl}^{-}\gt\mathrm{SO}_4^{2-}\gt\mathrm{Cl}^{-}$
• Correct answer
  D

  $\mathrm{Al}^{3+}\gt\mathrm{Ba}^{2+}\gt\mathrm{Na}^{+}$

Hence, the correct answer is option: 'D'.