12. One rope with weight 2.0 kg and length 10.0 m is tied on a shelf and stretched taut by a 98 kg box at the bottom. What is the speedv of a transverse wave on the rope? (Gravitational acceleration g = 10 m/s2)
(A) 10.0 m/s
(B) 10.7 m/s
(C) 70.0 m/s
(D) 70.7 m/s
(E) 100.0 m/s