A, in the process of rotation, the linear speed of the big gear and the small gear is equal. The big gear rotates clockwise, and so does the small gear, so A is wrong;

B, speed is related to the direction, so the linear speed of each tooth of the pinion is different, so B is wrong;

C, according to v=wr, and the linear velocity is equal, the angular velocity is inversely proportional to the radius, and c is correct;

D, according to centripetal acceleration A = V2R, the linear velocity is equal, and the ratio of centripetal acceleration is inversely proportional to the radius, so D is wrong.

So choose: C.