Somebody help me with this please very much appreciated

The answer for the following answer is explained below.
The answer is NH_{4} ^{+}
Explanation:
Bronsted-Lowry acid :
It is a solution that donates protons, and is known as a proton donor.It donates protons in the form of hydrogen ion([tex]H^{+}[/tex]).This is reinforced by the definition of an acid ,which is a solution that has hydrogen ions.
In Bronsted-Lowry aci it must contain a hydrogen io that it can give up.When the acid gives a hydrogen ion,the charge of an acid decreases.
Here,
NH_{4} ^{+} loses one hydrogen ion and forms ammonia molecule.
So therefore the Bronsted-Lowry acid is NH_{4} ^{+}.