I claim the ornamental design for a drying rack, as shown and described.
FIG. 1 is a frontal perspective view of the drying rack.
FIG. 2 is a front elevation view.
FIG. 3 is a right side elevation view.
FIG. 4 is a top plan view.
FIG. 5 is a bottom plan view.
FIG. 6 is a sectional view along lines 6-6 of FIG. 4.
FIG. 7 is a sectional view along lines 7-7 of FIG. 4; and,
FIG. 8 is a perspective view showing the drying rack with items to be dried in dotted configuration for purposes of showing the environment of the drying rack.