The ornamental design for a fork, as shown and described.
FIG. 1 is a perspective view of a fork showing our new design;
FIG. 2 is another perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top view thereof;
FIG. 8 is a bottom view thereof;
FIG. 9 is a perspective view thereof, showing a first status while in use; and,
FIG. 10 is a perspective view thereof, showing a second status while in use.
The dashed broken lines illustrate portions of the fork that form no part of the claimed design. The dashed broken lines showing an elongated handle in FIG. 9 and a shortened handle in FIG. 10 are for the purpose of illustrating environmental structure, and form no part of the claimed design.