Which frequency of microwave is used by a microwave oven to cook food (in $GHz$)?

The frequencies of $X-$rays,$\gamma-$rays and ultraviolet rays are respectively $p, q$ and $r$. Then which of the following is correct?

Microwaves are used in the following:

Arrange the following electromagnetic radiations per quantum in the order of increasing energy :-
$A$ : Blue light
$B$ : Yellow light
$C$ : $X$-ray
$D$ : Radiowave

Why does human skin darken when exposed to sunlight for a long period of time?

Match List $I$ with List $II$ of electromagnetic waves with their corresponding wavelength ranges:

List $I$	List $II$
$(A)$ Microwave	$(I)$ $400\,nm$ to $1\,nm$
$(B)$ Ultraviolet	$(II)$ $1\,nm$ to $10^{-3}\,nm$
$(C)$ $X$-Ray	$(III)$ $1\,mm$ to $700\,nm$
$(D)$ Infra-red	$(IV)$ $0.1\,m$ to $1\,mm$

Choose the correct answer from the options given below: