The ornamental design for a bra, as shown and described.
FIG. 1 is a front view of a bra according to the design;
FIG. 2 is a rear view thereof;
FIG. 3 is a front perspective view thereof;
FIG. 4 is a rear perspective view thereof; and,
FIG. 5 is a front perspective view thereof shown in use.
The broken lines shown in the drawings are for illustrating environmental structure and form no part of the claimed design. The cross-hatching shown on the inner portion on the front of the bra and on the middle strap on the back of the bra represents a transparent, translucent, or see-through mesh or sheer fabric only and does not represent any particular colour, material, texture, pattern, or finish of mesh or sheer fabric.