Identify the correct statement from the following.

• A
  $Lithium$ chloride is deliquescent and crystallises as a hydrate,$LiCl \cdot H_{2}O$.
• B
  The order of hydration enthalpies of alkaline earth cations is $Be^{2+} < Mg^{2+} < Ca^{2+} < Sr^{2+} < Ba^{2+}$.
• C
  $Lithium$ and $Magnesium$ show some similarities in their physical properties as they are diagonally placed in the periodic table.
• D
  $Lithium$ is the softest among all alkali metals.