If E and B represent electric and magnetic field vectors of the electromagnetic wave, the direction of propagation of the electromagnetic wave is along:

1. E

2. B

3. B x E

4. E x B

(d)
Hint: The electric field and magnetic field are perpendicular to each other in an electromagnetic wave.
Step 1: The direction of propagation of the electromagnetic wave is perpendicular to both electric field vector E and magnetic field vector B, i.e., in the direction of E x B. This can be seen by the diagram given below.
Here, the electromagnetic wave is along the z-direction which is given by the cross product of E and B.