Answer:
HNO3
Explanation:
The ability of an acid to act as a Brownstead-Lowry acid depends on it's proton donation ability.
A Brownstead-Lowry acid is a specie that donates hydrogen ions in solution.
Considering all the chemical species listed among the options, HNO3 has the greatest hydrogen donation ability. It then follows that HNO3 is the strongest Brownstead-Lowry acid among the species listed.