25. As shown in Figure 6, a small ball with a diameter of 4 inches rolls along a track starting from point $A$, and the track consists of three semicircles. It is known that the radii of the three semicircles are $R_{1}=100$ inches, $R_{2}=60$ inches, $R_{3}=80$ inches. If the ball remains in contact with the track and rolls without falling off, then the distance traveled by the center of the ball from point $A$ to $B$ is ( ).
(A) $238 \pi$
(B) $240 \pi$
(C) $260 \pi$
(D) $280 \pi$
(E) $500 \pi$
25. A.

Note that, the diameter of the ball is 4 inches.
If it rolls on the inside track of a semicircle with radius $R$ inches, then the path of the ball's center is a semicircle with radius $R-2$ inches; if it rolls on the outside track of a semicircle with radius $R$ inches, then the path of the ball's center is a semicircle with radius $R+2$ inches.
Therefore, the distance traveled by the center of the ball from point $A$ to $B$ is
$$
(100-2) \pi+(60+2) \pi+(80-2) \pi=238 \pi \text {. }
$$