We claim the ornamental design for a bed, as shown and described.
FIG. 1 is a front, right perspective view of the bed, according to an embodiment;
FIG. 2 is a front side view of the bed, according to the embodiment;
FIG. 3 is a right side view of the bed, according to the embodiment;
FIG. 4 is a back side view of the bed, according to the embodiment;
FIG. 5 is a left side view of the bed, according to the embodiment;
FIG. 6 is a top side view of the bed, according to the embodiment; and,
FIG. 7 is a bottom side view of the bed, according to the embodiment.
The evenly dashed broken lines of the various figures of the bed are directed to the environment and are for illustrative purposes only; the evenly dashed broken lines form no part of the claimed design.