Consider three metal chlorides $x$,$y$ and $z$,where $x$ is water soluble at room temperature,$y$ is sparingly soluble in water at room temperature and $z$ is soluble in hot water. $x$,$y$ and $z$ are respectively:

• A
  $MgCl_{2}$,$AgCl$ and $AlCl_{3}$
• B
  $AgCl$,$Hg_{2}Cl_{2}$ and $PbCl_{2}$
• C
  $AlCl_{3}$,$PbCl_{2}$ and $BaCl_{2}$
• D
  $CuCl_{2}$,$AgCl$ and $PbCl_{2}$