The ornamental design for a clock, as shown and described.
The claimed clock is used for measuring or indicating time. It is a mechanical or electronic device which has moving hands and a moving figurine of a surfer which moves out of, and into, a wave, at alarm times.
FIG. 1 is a front elevational view of a clock showing my new design;
FIG. 2 is a right side view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a rear elevational view thereof; and,
FIG. 5 is a top plan view thereof.
The portions shown in broken lines are included for illustrative purposes only and form no part of the claimed design.