The ornamental design for a light-emitting diode, as shown and described here.
FIG. 1 is a perspective view of the light-emitting diode in accordance with my new design, showing an upper surface and side surfaces as viewed from diagonally above;
FIG. 2 is a perspective view thereof, showing a bottom surface and side surfaces as viewed from diagonally above;
FIG. 3 is a front elevation view ,the rear elevation view being a mirror image thereof;