The velocity components of a two dimensional plane motion of a fluid are $:u=\dfrac{y^3}{3}+2x—x^2y$ and $v=xy^2-2y-\dfrac{x^3}{3}$. The correct statement is:

- Fluid is incompressible and flow is irrotational
- Fluid is incompressible and flow is rotational
- Fluid is compressible and flow is irrotational
- Fluid is compressible and flow is rotational