FIG. 1 is a perspective view of a bed; FIG. 2 is a front elevational view of the bed; FIG. 3 is a rear elevational view of the bed; FIG. 4 is a top elevational view of the bed; FIG. 5 is a bottom elevational view of the bed; FIG. 6 is a side elevational view of the bed; and, FIG. 7 is a side elevational view of the bed. The broken lines are for environmental purposes only and form no part of the claimed design.