We claim the ornamental design for a rack, as shown and described.
FIG. 1 is a top perspective view of an embodiment of the claimed design;
FIG. 2 is a bottom perspective view of the claimed design of FIG. 1;
FIG. 3 is a top view of the claimed design of FIG. 1;
FIG. 4 is a bottom view of the claimed design of FIG. 1;
FIG. 5 is a front view of the claimed design of FIG. 1;
FIG. 6 is a rear view of the claimed design of FIG. 1;
FIG. 7 is a left side view of the claimed design of FIG. 1; and,
FIG. 8 is a right side view of the claimed design of FIG. 1.
The ornamental design which is claimed is shown in solid lines in the drawings. The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design. The dash-dot lines in the drawings represent the boundaries of the claimed design and form no part of the claimed design.