A 30-Kg and a 5

Multiple Choice

A 3.0-kg and a 5.0-kg box rest side-by-side on a smooth,level floor.A horizontal force of 32 N is exerted on the 5.0-kg box pushing it against the 3.0-kg box,and,as a result,both boxes slide along the floor.How hard do the two boxes push against each other?

A) 12 N
B) 20 N
C) 24 N
D) 32 N
E) 0 N