An epicyclic gear train is shown schematically in the adjacent figure. The sun gear 2 on the input shaft is a 20 teeth external gear. The planet gear 3 is a 40 teeth external gear. The ring gear 5 is a 100 teeth internal gear. The ring gear 5 is fixed and the gear 2 is rotating at 60 rpm ccw (ccw = counter – clockwise and cw = clockwise) The arm 4 attached to the output shaft will rotate at

• A. 10 rpm ccw
• B. 10 rpm cw
• C. 12 rpm cw
• D. 12 rpm ccw