The specific heat of \[Ar\] at constant volume is \[0.075\text{ }k{{g}^{-1}}{{K}^{-1}}.\] Calculate the atomic weight \[~\left( R=2\text{ }cal\text{ }mo{{l}^{-1}}{{K}^{-1}} \right)\]

• A. 40 
• B. 40.4  
• C. 40.2  
• D. 40.8