[单选题]
A +3.0-C charge is at the origin and a +9.0-C charge is at x20pdobp8 ufam*l:u . *n/ ,e 9s0v,kzojppk us = 4.0 m. Whd 3/f3y6swkv ,1s zcm6mwde.yere on the x-axis can a third charge be placed w mdsszc fm /,kyv wd6e.16y33so 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