Consider a Capacitor That Consists of Two Parallel Plates,one of Which

Consider a capacitor that consists of two parallel plates,one of which can move relative to the other.Air fills the space between the plates,the capacitance is 45.2 pF when the separation between plates is d = 0.360 cm.A battery with potential difference V=12.0 V is connected to the plates to fully charge them and then it is disconnected from the plates.The plates are moved to a new separation,d' and as a result the new potential difference V' between the plates is 10.0 V.What is the new plate separation,d'?

A) 0.420 cm
B) 0.240 cm
C) 0.270 cm
D) 0.180 cm
E) 0.300 cm