Answer
d. NH4+1 and HOH
Explanation
By definition, A Brønsted-Lowry acid is any species that can donate a proton, H+, and a base is any species that can accept a proton.
In terms of chemical structure, this means that any Brønsted-Lowry acid must contain a hydrogen that can dissociate H+. In order to accept a proton, a Brønsted-Lowry base must have at least one lone pair of electrons to form a new bond with a proton.
Therefore, the two Bronsted- Lowry acids in the given equation are:
d. NH4+1 and HOH
