A 6-V Battery Is Connected Across a Capacitor Through a Switch

A 6-V battery is connected across a capacitor through a switch which is initially open.The 90 µC charge flows from the battery to the capacitor when the switch is closed.The capacitance of the capacitor is

A) 0.67 µF.
B) 15 µF
C) 20 µF
D) 54 µF.
E) 30 µF.