The ornamental design for a seat, as shown and described.
FIG. 1 is a top plan view of the new design.
FIG. 2 is a front elevation view of the new design.
FIG. 3 is a side elevation view of the new design; the opposite side being the mirror image thereof.
FIG. 4 is a bottom plan view of the new design.
FIG. 5 is a rear elevation view of the new design.
FIG. 6 is a front perspective view of the new design.
FIG. 7 is a rear perspective view of the new design; and,
FIG. 8 is an environment view showing the front perspective view of the new design incorporated into an assembly.
The broken lines shown in the drawings illustrate portions of the seat that form no part of the claimed design or are shading lines that represent the approximate three-dimensional contour of the claimed design and are not intended to indicate surface decoration.