In the Figure $+ 4.0 - \mu \mathrm { C }$

Multiple Choice

In the figure, $+ 4.0 - \mu \mathrm { C }$ and $- 4.0 - \mu \mathrm { C }$ point charges are located as shown. Now an additional $+ 2.00 - \mu \mathrm { C }$ point charge is placed at point $\mathrm { A }$ . What is the electric potential energy of this system of three charges, relative to infinity? $\left( k = 1 / 4 \pi \varepsilon _ { 0 } = 8.99 \times 10 ^ { 9 } \mathrm {~N} \cdot \mathrm { m } ^ { 2 } / \mathrm { C } ^ { 2 } \right)$

A) $+ 26.4 \mathrm {~mJ}$
B) $- 264 \mathrm {~mJ}$
C) $+ 264 \mathrm {~mJ}$
D) $0.00 \mathrm {~J}$
E) $- 26.4 \mathrm {~mJ}$