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