Considering choices;
a. CH3COOH
b. H2S
c. H2PO4
d. HNO3
The answer would be HNO3; this is because it the strongest acid. Strong acids are acids that are fully ionized while weak acids are only partially ionized. At the same concentrations, strong acids have a higher concentration of hydrogen than weak acids. Examples of strong acids include; hydrocloric acid and nitric acid, while weak acids include; ethanoic acids.