Answer the following question given this paragraph: 

A monoprotic acid is an acid that contains only one ionizable hydrogen. Hydrochloric acid and acetic acid are monoprotic acids. A polyprotic acid is an acid that contains multiple ionizable hydrogens. Most common polyprotic acids are either diprotic (such as H 2 SO 4 ) or triprotic (such as H 3 PO 4 ).


Q: Which acid contains only one ionizable hydrogen?

 Choices:

- citric acid

- lactic acid

- amino acid

- monoprotic acid

A:
monoprotic acid
