I claim ornamental design for a sock, as shown and described.
FIG. 1 is a lower left side perspective view of a sock showing my new design with the flap in a closed but outwardly pulled configuration;
FIG. 2 is an upper left side perspective view of the sock of FIG. 1 with the flap in an opened and outwardly pulled configuration;
FIG. 3 is an upper right perspective view of the sock of FIG. 1 with the flap in the opened configuration and in an alternate flexed state;
FIG. 4 is a bottom view of the sock of FIG. 3;
FIG. 5 is a top plan view of the sock of FIG. 1 in its closed configuration;
FIG. 6 is top perspective view of the sock of FIG. 1 in its open configuration and in another alternative flexed state;
FIG. 7 is a left-side elevation view of the sock of FIG. 1 in its closed configuration; and,
FIG. 8 is a right-side elevation view of the sock of FIG. 7.
The broken lines representing the human hand and the dashed lines on the sock are for illustrative purposes only and form no part of the claimed design.