The correct van der Waals equation for 1 mole of a real gas is:
A $\left(p+\dfrac{a}{V^2}\right)(V-b)=RT$
B $\left(p+\dfrac{V^2}{a}\right)(V-b)=RT$
C $\left(p+\dfrac{an^2}{V^2}\right)(V^2-nb)=RT$
D $\left(p+\dfrac{an^2}{V}\right)(V-nb)=nRT$