Two point charges of +4μC are placed at (0,+0.30m) and (0,−0.30m) on the y-axis. A test charge of +2μC is kept at (+0.40m,0). Taking k=9×109N m2/C2, the x-component of the net electrostatic force on the test charge is closest to
a) +0.92N
b) +0.23N
c) +0.46N
d) −0.46N