Three blocks A, B and C, of masses 4 kg , 2 kg and 1 kg respectively, are in contact on a

Three blocks A, B and C, of masses 4 kg , 2 kg and 1 kg respectively, are in contact on a frictionless surface, as shown. If a force of 14 N is applied on the 4 kg block, then the contact force between A and B is: NEET 2015
2 N
6 N
8 N
18 N