Two Point Charges of Values +3 $\mu$ C and +66 $\mu$ C, Respectively, Are Separated by 0

Two point charges of values +3.4 $\mu$ C and +6.6 $\mu$ C, respectively, are separated by 0.20 m. What is the potential energy of this 2-charge system? (k_e = 8.99* 10⁹ N.m²/C²)

A) "+1.0 J"
B) "-5.0 J"
C) "-0.75 J"
D) "+0.50 J"