From the following figures choose the figure which is different from the others:

Concept: In this odd-one-out format, every figure shows a smaller shape enclosed inside a larger shape. The rule that unites three of the four figures is containment: the outline of the smaller shape lies entirely within the outline of the larger shape, with no crossing or overlap. The odd figure is the one where this containment relationship fails.

Application: Checking each figure against the containment rule:

• Figure 1: a smaller circle is drawn fully inside a larger circle (concentric); the small circle's boundary never touches or crosses the large circle's boundary.

• Figure 2: a smaller triangle is drawn fully inside a larger triangle, again with the inner outline staying clear of the outer outline.

• Figure 3: a rectangle is drawn fully inside a larger rounded-corner shape, once more completely enclosed.

• Figure 4: a smaller diamond overlaps the larger diamond near the top; its outline crosses over and pokes out above the larger diamond's top edge, so it is not fully enclosed inside the larger diamond.

Cross-check: Tracing each inner shape's outline against its outer shape confirms this: in Figures 1, 2 and 3 the inner outline stays inside the outer outline at every point, but in Figure 4 part of the inner diamond's outline lies outside the outer diamond's boundary.

Since containment holds in Figures 1, 2 and 3 but fails in Figure 4, Figure 4 is the figure that is different from the rest.