A plane electromagnetic wave travels in vacuum along y-direction. At the same instant, the direction of Electric and magnetic fields are:

E along z-axis; B along x-axis

The correct answer is Option (3) → E along z-axis; B along x-axis

The electric field and the magnetic field must be perpendicular to the direction of wave propagation (y-direction).

→ The direction of $\vec E$ is along z-axis.

→ The direction of $\vec B$ is along x-axis.