[单选题]
A +3.0-C charge is at the origin and a +9.0-C charcr4k/guo s c.gz na,z;*gu7 c/ge is atj+fgm*74yfvji ez: -mn , pbe* x = 4.0 m. Where on the x-axis can a third charzjnbme :yffe,-p*v 4 *7g+jmige be placed so the net force on it is zero?
A. x = 0.50 m
B. x = 0.60 m
C. x = 1.5 m
D. x = 2.4 m
