The ornamental design for an arm of a stand, as shown and described.
FIG. 1 is a front elevation view of an arm of a stand showing our new design, wherein the arm is shown in a first position relative to the stand and an arm lever which are illustrated as environmental subject matter;
FIG. 2 is a rear elevation view thereof;
FIG. 3 is a left side elevation view thereof, wherein the right side elevation view is a mirror image of FIG. 3;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a front right isometric view thereof;
FIG. 7 is an additional left side elevation view thereof, wherein the arm is shown in a second position relative to the stand and arm lever which are illustrated as environmental subject matter, and wherein the right side is a mirror image of FIG. 7;
FIG. 8 is an additional left side elevation view thereof, wherein the arm is shown in a third position relative to the stand and arm lever which are illustrated as environmental subject matter, and wherein the right side is a mirror image of FIG. 8;
FIG. 9 is an additional front right isometric view thereof, further illustrating a display as environmental subject matter, wherein the arm is shown in the first position; and,
FIG. 10 is an additional front right isometric view thereof, further illustrating a display as environmental subject matter, wherein the arm is shown in the third position.
The broken lines in FIGS. 1 through 10 illustrate environmental subject matter and form no part of the claimed design.