There is a curve in which the length of the perpendicular from the origin to tangent at any point is equal to abscissa of that point. Then,
(a) $x^{2}+y^{2}=2$ is one such curve
(b) $y^{2}=4 x$ is one such curve
(c) $x^{2}+y^{2}=2 c x$ (c parameters) are such curves
(d) there are no such curves