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 with front and right side surfaces as obliquely viewed from above;
FIG. 2 is a perspective view thereof, showing a bottom surface with rear and left side surfaces as obliquely viewed from above;
FIG. 3 is a front elevation view thereof; the rear elevation being a mirror image to FIG. 3;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof; and,
FIG. 6 is a right side view thereof; the left side being identical to FIG. 6.