Bottle stopper

FIG. 1 is a perspective view of a bottle stopper;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a third perspective view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a right elevation view thereof;

FIG. 6 is a front elevation view thereof;

FIG. 7 is a left elevation view thereof;

FIG. 8 is top plan view thereof; and,

FIG. 9 is a bottom plan view thereof.

The broken lines are shown for the purpose of illustrating parts of the article that form no part of the claimed design.