c
From the two mutually perpendicular \(S.H.M. 's\), the general equation of Lissajous figure \(\frac{{{x^2}}}{{{A^2}}} + \frac{{{y^2}}}{{{B^2}}} - \frac{{2xy}}{{AB}}\cos \,\delta = {\sin ^2}\,\delta\) \(x = A\,\sin \,\left( {at + \delta } \right)\) \(y = B\,\sin \,\left( {bt + r} \right)\) Clearly \(A\ne B\) hence ellipse