The coefficient of friction between 4 kg and 5 kg blocks is 0.2 and between 5 kg block and ground is 0.1 respectively. Choose the correct statements 

(A) Minimum force needed to cause system to move on ground is 17 N 
(B) When force F = 4N, static friction at all surfaces 1 4 N to keep system at rest. 
(C) Maximum acceleration of 4 kg block is 2 m/$s^2$
(D) Slipping between 4 kg and 5 kg block starts when F is 17 N.