An Uncharged Parallel Plate Capacitor with an Air Gap Is

An uncharged parallel plate capacitor with an air gap is connected to a 6.0-V battery.After charging,the energy stored in the capacitor is 40 nJ.Without disconnecting the capacitor from the battery,a dielectric material is inserted into the air gap and an additional 200 nJ of energy flows from the battery to the capacitor.What is the dielectric constant of the material?

A) 0.2
B) 1.0
C) 3.0
D) 5.0
E) 6.0