Consider the given data $:$
$(a) \ HCl_{(g)} + 10 \ H_2O_{(l)} \rightarrow HCl \cdot 10 \ H_2O \quad \Delta H = -69.01 \ kJ \ mol^{-1}$
$(b) \ HCl_{(g)} + 40 \ H_2O_{(l)} \rightarrow HCl \cdot 40 \ H_2O \quad \Delta H = -72.79 \ kJ \ mol^{-1}$
Choose the correct statement $:$

• A
  Dissolution of gas in water is an endothermic process.
• B
  The heat of solution depends on the amount of solvent.
• C
  The heat of dilution for the $HCl$ ($HCl \cdot 10 \ H_2O$ to $HCl \cdot 40 \ H_2O$) is $-3.78 \ kJ \ mol^{-1}$.
• D
  The heat of formation of $HCl$ solution is represented by both $(a)$ and $(b)$.