Modulation is a process of superposing

Given below are two statements:
Statement-$I$: $A$ speech signal of $2 \, kHz$ is used to modulate a carrier signal of $1 \, MHz$. The bandwidth requirement for the signal is $4 \, kHz$.
Statement-$II$: The sideband frequencies are $1002 \, kHz$ and $998 \, kHz$.
In the light of the above statements,choose the correct answer from the options given below:

For an amplitude modulated wave,the maximum amplitude is found to be $10 \,V$ while the minimum amplitude is found to be $4 \,V$. The modulation index is

$A$ message signal of frequency $f_m$ is used to modulate a carrier of frequency $f_c$. If the sidebands are $f_1$ and $f_2$, then the ratio $\frac{f_c}{f_m}$ is:

The layer of the atmosphere which efficiently reflects high frequency waves particularly at night is

In general,a transmitting antenna is........