The Work Done to Assemble Four Identical -3

Multiple Choice

The work done to assemble four identical -3.0 nC charges at the corners of a square of side 4.0 cm is

A) 1.1*10^-7 J.
B) -1.1 * 10^-7 J.
C) 1.1 * 10^-5 J.
D) -1.1 * 10^-5 J.
E) 4.4 * 10^-7 J.