Which statement correctly relates two substances in this chemical equation? NH₃ + H₂O ⇌ OH⁻ + NH⁴⁺
A. H₂O is the conjugate base of OH−.
B. H₂O is the conjugate acid of NH₃.
C. NH⁴⁺ is the conjugate acid of NH₃.
D. NH₃ is the conjugate acid of NH⁴⁺ .
E. OH⁻ is the conjugate base of NH₃.