The $x$ and $y$ velocity components of a two dimensional flow field are, $u=\frac{c y}{x^{2}+y^{2}}, v=\frac{c x}{x^{2}+y^{2}},$ where $c$ is a constant. The streamlines are a family of
(A) hyperbolas
(B) parabolas
(C) ellipses
(D) circles
The $x$ and $y$ velocity components of a two dimensional flow field are, $u=\frac{c y}{x^{2}+y^{2}}, v=\frac{c x}{x^{2}+y^{2}},$ where $c$ is a constant. The streamlines are a family of
(A) hyperbolas
(B) parabolas
(C) ellipses
(D) circles