Which of the Following Statement(s) Is/are Correct

Multiple Choice

Which of the following statement(s) is/are correct?
(i) HClO₄ is an example of an oxoacid.
(ii) H₃PO₄ is a diprotic acid.
(iii) Distribution diagrams relate pH with pK_a of a polyprotic acid.

A) Only statement (i)
B) Statements (i) and (iii)
C) Statements (ii) and (iii) .