Đáp án đúng: B HCl CaCl2 AgCl. $\begin{array}{l}{2HCl}\,{+}\,{Ca}\,\xrightarrow{{}}\,{CaC}{{{l}}_{{2}}}\,{+}\,{{{H}}_{{2}}}\uparrow \\{2AgN}{{{O}}_{{3}}}\,{+}\,{CaC}{{{l}}_{{2}}}\,\xrightarrow{{}}\,{Ca(N}{{{O}}_{{3}}}{{{)}}_{{2}}}\,{+}\,{2AgCl}\downarrow \end{array}$