Internal energy of a gas obeying Van-Der-Wall's equation of state, $$\left( {{\text{p}} + \frac{{\text{a}}}{{{{\text{v}}^2}}}} \right)\left( {{\text{V}} - {\text{b}}} \right) = {\text{RT,}}$$ depends upon its
A. Pressure & temperature
B. Pressure & specific volume
C. Temperature & specific volume
D. Temperature only
Answer: Option A

Answer is C.
In case of ideal gas equation internal energy is the function of temperature but in this case of van der Wall's equation specific volume is considered therefore it's the function of both temperature and specific volume.