Conjugate base for Bronsted acids ${\mathrm{H}}_2\mathrm{O}$ and HF are

• A

  ${\mathrm{H}}_3{\mathrm{O}}^{+}\mathrm{and} {\mathrm{H}}_2{ \mathrm{F}}^{+},\mathrm{respectively}$

• B

  ${\mathrm{OH}}^{-}\mathrm{and} {\mathrm{H}}_2{ \mathrm{F}}^{+},\mathrm{respectively}$

• C

  ${\mathrm{H}}_3{\mathrm{O}}^{+}\mathrm{and} {\mathrm{F}}^{-},\mathrm{respectively}$

• D

  ${\mathrm{OH}}^{-}\mathrm{and} {\mathrm{F}}^{-},\mathrm{respectively}.$