The ornamental designs for a wrench, as shown and described.
FIG. 1 is a top left perspective view of a wrench;
FIG. 2 is a front view of the wrench;
FIG. 3 is a rear view of the wrench;
FIG. 4 is a right side view of the wrench;
FIG. 5 is a left side view of the wrench;
FIG. 6 is a top view of the wrench; and,
FIG. 7 is a bottom view of the wrench.
The dashed lines in FIGS. 1, 2, 4, 5, and 6 represent environmental structure and form no part of the claimed designs. All other surface(s) or portion(s) of my designs not shown in the FIGURES or otherwise described in the specification form no part of the claimed designs.