নিচের কোনটি আয়নিক এবং সমসত্ত্ব সাম্যাবস্থার উদাহরণ?

$\mathrm{NH}_{4} \mathrm{Cl}(\mathrm{s}) \rightleftharpoons \mathrm{NH}_{3}(\mathrm{~g})+\mathrm{HCl}(\mathrm{g})$

$\mathrm{NH}_{4} \mathrm{Cl}(\mathrm{aq}) \rightleftharpoons \mathrm{NH}_{4}^{+}(\mathrm{aq})+\mathrm{Cl}^{-}(\mathrm{aq})$

$\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}(\mathrm{~s}) \rightleftharpoons \mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}(\mathrm{aq})$

$\mathrm{CaCO}_{3}(\mathrm{~s}) \rightleftharpoons \mathrm{Ca}^{2+}(\mathrm{g})+\mathrm{CO}_{3}^{2-}(\mathrm{g})$