Among the compounds H₃PO₄(aq), HBr(aq), Fe(OH)₃, H₂SO₄(aq), Ca(HCO₃)₂, and KNO₃, which compound is most likely to produce a solution with a pH less than 7?
A) H₃PO₄(aq)
B) HBr(aq)
C) Fe(OH)₃
D) H₂SO₄(aq)