24. As shown in Figure 2, a circle with a radius of 2 is divided into four equal arcs, which are then arranged to form a star shape. The ratio of the area of this shape to the area of the original circle is ( ).
(A) $\frac{4-\pi}{\pi}$
(B) $\frac{1}{\pi}$
(C) $\frac{\sqrt{2}}{\pi}$
(D) $\frac{\pi-1}{\pi}$
(E) $\frac{3}{\pi}$
24. A.

As shown in Figure 6.
Notice that, the area of the star-shaped figure is the difference between the area of the square with side length 4 and the area of the circle.
Therefore, the required ratio of the areas is
$$
\frac{4^{2}-4 \pi}{4 \pi}=\frac{4-\pi}{\pi} .
$$