A Point Charge Is Moving with Speed 2 $\times$ 10⁷ M/s Along the X Axis

Multiple Choice

A point charge is moving with speed 2 $\times$ 10⁷ m/s along the x axis.At t = 0,the charge is at x = 0 m and the magnitude of the magnetic field at x = 4 m is B₀.The magnitude of the magnetic field at x = 4m when t = 0.1 $\mu$ s is

A) B₀/2
B) B₀
C) B₀/4
D) 2B₀
E) 4B₀