Answer
Please see the work below.
Work Step by Step
(a) We know that the electric field propagates in the direction of oscillation of charge; thus, the direction of oscillation of the electric field is along the z-axis.
(b) In the electromagnetic wave, the electric and magnetic field are mutually perpendicular to each other in all conditions and the magnetic field is perpendicular to the direction of propagation. Hence the magnetic field oscillates in the x-direction.
(c) The electromagnetic wave propagates in the +y direction from the origin to the observer's location and it also propagates in the +y direction after reaching the observer.
