A 65-N box rest on a perfectly smooth surface. The minimum force needed to start the box moving is

A) 65 N

B) 6.5 N

C) 650 N

D) any horizontal force greater than zero

when you say "perfectly smooth", I understand that to mean there's no friction. If that's true, then ANY net horizontal force acting on the box makes it start moving. (D) Naturally, the greater the force is, the faster the box speeds up. That's because F = m A.