This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Monoprotic acid are - 
Select and explain. 
A. Formic acid, B. Acetic acid, C. Nitric acid, D. All of these
D: All of these
Answer: D: All of these 
Explanation: Monapratic acids (HA) can donate 1 proton (H+) per molecule. Examples are hydrochloric acid (HCl), nitric acid (HNO3), formic acid, acetic acid, lactic acid and benzoic acid.
Polyprotic acids can donate more than one protons (H+) per molecules. These can be divided into :-

(i) Diprotic acid (H2A) :- These can donate upto 2 protons (RE) per molecule. Examples are carbonic acid, sulphuric acid, succinic acid and glutaric acid.
(iii) Triprotic acid (H3A) :- These can donate upto 3 protons (H+) per molecule. Examples are phosphoric acid and citric acid.