The streamlines for this flow are given by the family of curves

Question

For a certain two-dimensional incompressible flow, velocity field is given by 2xy $\hat{i}-y^{2} \hat{j}$.  The streamlines for this flow are given by the family of curves                                                                                                   

      (a) x²y² = constant

      (b) xy² = constant

      (c) 2xy – y² = constant

      (d) xy = constant