For real numbers $t,$ the point
\[(x,y) = (5 \cos 2t, 3 \sin 2t)\]is plotted.  All the plotted points lie on what kind of curve?

(A) Line
(B) Circle
(C) Parabola
(D) Ellipse
(E) Hyperbola

Enter the letter of the correct option.
Let $x = 5 \cos 2t$ and $y = 3 \sin 2t.$  Then
\[\frac{x^2}{25} + \frac{y^2}{9} = \cos^2 2t + \sin^2 2t = 1,\]so all the plotted points lie on an ellipse.  The answer is $\boxed{\text{(D)}}.$