The ornamental design for a sink, as shown and described.
FIG. 1 is a front, top, perspective view of a sink showing my new design;
FIG. 2 is a rear, bottom, perspective view of the sink shown in FIG. 1;
FIG. 3 is a front elevational view of the sink shown in FIG. 1;
FIG. 4 is a rear elevational view of the sink shown in FIG. 1;
FIG. 5 is a left-side elevational view of the sink shown in FIG. 1, the right-side elevational view being a mirror of the left-side;
FIG. 6 is a top plan view of the sink shown in FIG. 1; and,
FIG. 7 is a bottom plan view of the sink shown in FIG. 1.
The broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.