[单选题]
Q1 = 6.0 nC is at (0.30 m, 0); Q2 = -1.0 nC is at (nx1f9y08nly-3lb;go bs yw(a0, 0.10 m); Q3 = 5.0 nC yc6ji :ue-wtqi/v.d: is at (0, 0). W:ti6 v/w ed.j: -yuiqchat is the magnitude of the net force on the 5.0 nC charge?
A. $3.0 \times 10^{-6} \; N$
B. $4.5 \times 10^{-6} \; N$
C. $5.4 \times 10^{-6} \; N$
D. $7.2 \times 10^{-6} \; N$