A flat surface of a thin uniform disk A of radius R is glued to a horizontal table. Another thin uniform disk B of mass M and with the same radius R rolls without slipping on the circumference of A, as shown in the figure. A flat surface of B also lies on the plane of the table. The center of mass of B has fixed angular speed about the vertical axis passing through the center of A. The angular momentum of B is nMoR with respect to the center of A. Which of the following is the value of n ? (A) 2 (B) 5 A B (C) 7/2 (D) 9/2