The ornamental design for a mop, as shown and described.
Description
FIG. 1 is a rear left perspective view of a mop, wherein the remainder of the mop is unclaimed and omitted for clarity;
FIG. 2 is a front view thereof;
FIG. 3 is a right view thereof;
FIG. 4 is a left view thereof; and,
FIG. 5 is a rear view thereof.
The dot-dash-dot broken line showing represents unclaimed boundaries of the claimed design. The dot-dot broken line showing represents environmental structure and forms no part of the claimed design.