20-1. Choose the correct statement(s) among the following. (A) SnCl_(2)*2H_(2)O is a reducing agent. (B) SnO_(2) reacts with KOH to form K_(2)[Sn(OH)_(6)]. (C) A solution of PbCl_(2) in HCl contains Pb^(2+) and Cl^(') ions. (D) The reaction of Pb_(3)O_(4) with hot dilute nitric acid to give PbO_(2) is a redox reaction.