A mass of $20$Kgmol is cooled from $200K$ to $100K$ and the change in internal energy is $400KJ.$ What is the heat capacity at constant volume?

Select one:

$$ a$.$ Degree Celsius$)($Kg mole$)$

b$.400\frac{J}{?}($Degree Celsius$)($Kg mole$)$

c$.$ Degree Celsius$)($Kg mole$)$

d$.$ Degree Celsius$)($Kg mole$)$