Help please time is short

A dielectric slab of dielectric 5 is inserted constant k = between the plates of a parallel-plate capacitor. The capacitance with the dielectric between the plates is 25 F. The charge on the capacitor plates is 100 C. The potential after the removal of the dielectric (in volts) is: Select one: a. 160 b. 20 c. 80 d. 40 e. 96