Which one is the incorrect explanation on electromagnetic $($EM$)$ waves?

a$.$ They consist of both electric and magnetic fields.

$($Answer:

b$.$ The direction of electric field at a given time is perpendicular to that of magnetic field.

c$.$ The ratio of electric field magnitude to magnetic field magnitude $(\frac{E}{B})$ varies over time.

d$.$ The direction of the EM wave propagation is perpendicular to that of electric field.

The distance between Earth and the Sun is $1\mathrm{.}50{10}^{11}m.$ How much time does it take for light to cover this distance? Find the closest answer.

$($Answer:

a$.500$ seconds

b$.200$ seconds

c$.4\mathrm{.}50{10}^{19}$ seconds

d$.0\mathrm{.}0002$ seconds