When a Capacitor Has a Charge of Magnitude 80 $\mu$ C on Each Plate the Potential Difference Across the Plates

Multiple Choice

When a capacitor has a charge of magnitude 80 $\mu$ C on each plate the potential difference across the plates is 16 V.How much energy is stored in this capacitor when the potential difference across its plates is 42 V?

A) 1.0 mJ
B) 4.4 mJ
C) 3.2 mJ
D) 1.4 mJ
E) 1.7 mJ