I claim the ornamental design for a cap, as shown and described.
FIG. 1 is a perspective view of a cap, showing my new design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a right-side elevational view thereof;
FIG. 5 is a front elevational view thereof;
FIG. 6 is a rear elevational view thereof; and,
FIG. 7 is a left-side elevational view thereof.
The broken lines representing a rectangular logo patch on the left side of the cap in FIGS. 1-3 and 5-7 depict environmental matter, and form no part of the claimed design. The remaining broken lines in the figures represent stitching, and are part of the claimed design. The stippling on the pair of tie ribbons in the figures represents a contrasting color and pattern to that shown on the remainder of the cap.