If the Z-Component of the Magnetic Field of an Electromagnetic

If the z-component of the magnetic field of an electromagnetic wave traveling in the +x direction through vacuum obeys the equation B_z(x,t) = (1.25 μT) cos[(3800 m^-1) x - (1.14 × 10-¹² rad/s) t],what is the largest that the y component of the electric field can be? (c = 3.0 × 10⁸ m/s)

A) 375 N/C
B) 4.17 × 10^-15 N/C
C) 3.75 × 10⁸ N/C
D) 4.17 × 10^-9 N/C
E) 1.25 × 10⁶ N/C