The ornamental design for a hook, as shown and described.
FIG. 1 is a perspective view of a hook showing my new design;
FIG. 2 is a front view of the hook of FIG. 1;
FIG. 3 is a rear view of the hook of FIG. 1;
FIG. 4 is a left side view of the hook of FIG. 1;
FIG. 5 is a right side view of the hook of FIG. 1;
FIG. 6 is a top view of the hook of FIG. 1;
FIG. 7 is a bottom view of the hook of FIG. 1;
FIG. 8 is a perspective view of the hook of FIG. 1; and,
FIG. 9 is an enlarged view of the tip of the hook of FIG. 1.
The broken line drawings of the images, text, and other elements shown in the figure are shown for illustrative purposes only and form no part of the claimed design. In addition, the surface shading, if any, illustrated in the drawings is provided merely to highlight the contour of the design; it is not intended to be illustrative of texture or gloss.