Which of the aqueous solution turns blue litmus red?

• A

  NH₄Cl

• B

  $\mathrm{Al}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6^{3+}$

• C

  $\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6^{3+}$

• D

  AII of these