Which one of the following statements is correct?

If $\overrightarrow E$ and $\overrightarrow B$ are the electric and magnetic field vectors of electromagnetic waves,then the direction of propagation of the electromagnetic wave is along the direction of:

The maximum electron density of the ionosphere layer in the morning is $10^{10} \ m^{-3}$. At noon,the maximum electron density increases to $2 \times 10^{10} \ m^{-3}$. What is the ratio of the critical frequency at noon to the critical frequency in the morning?

$A$ plane electromagnetic wave with a frequency of $30 \text{ MHz}$ travels in free space. At a particular point in space and time,the electric field is $6 \text{ V/m}$. The magnetic field at this point will be $x \times 10^{-8} \text{ T}$. The value of $x$ is ..... .

The electric field of a plane electromagnetic wave is given by $\overrightarrow{E} = E_{0}(\hat{x} + \hat{y}) \sin(kz - \omega t)$. Its magnetic field will be given by

This question has Statement-$1$ and Statement-$2$. Of the four choices given after the statements,choose the one that best describes the two statements.
Statement-$1$: Out of radio waves and microwaves,the radio waves undergo more diffraction.
Statement-$2$: Radio waves have a greater frequency compared to microwaves.