what is the correct answer

Question 4 1 pts Red laser light of wavelength 700 nm travels through vacuum in the -z direction. At some instant of time the magnetic field of this wave points in the ____ direction at point P. What is the direction of the electric field of this wave at the same time but at a point nm beyond point P in the -z direction? ty, 350 [ Choose | v ty, 700 [ Choose ] v +x, 700 [ Choose | v +x, 350 [ Choose ] v