We claim the ornamental design for a sink, as shown and described.
FIG. 1 is a front perspective view of an embodiment of the claimed design;
FIG. 2 is a rear perspective view of the embodiment of FIG. 1;
FIG. 3 is a front view of the embodiment of FIG. 1;
FIG. 4 is a rear view of the embodiment of FIG. 1;
FIG. 5 is a side view of the embodiment of FIG. 1;
FIG. 6 is another side view of the embodiment of FIG. 1;
FIG. 7 is a top view of the embodiment of FIG. 1; and,
FIG. 8 is a bottom view of the embodiment 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. Broken lines formed by equal length dashes show unclaimed subject matter. Broken lines formed by unequal length dashes (i.e., dash-dot) define bounds of the claimed design. The appearance of any portion of the article between the broken away symbols forms no part of the claimed design.