The following combination's comparable resistance is:

Resistance: The resistance of a conductor is the measurement of the resistance of the flow of electric current through that conductor. R stands for it.

Resistances can be combined primarily in two ways:

Resistances combined in series: Resistances in series are arranged so that the same current passes through two or more resistances when they are connected one after another.

The formula for the net resistance or equivalent resistance of resistances in series is:

Equivalent resistance, $R=R_1+R_2$

Resistances in parallel are combinations where the potential difference across two or more resistance terminals is equal and they are connected at the same two places.

The formula for the net resistance/equivalent resistance(R) of parallel resistances is:

$\frac{1}{R}=\frac{1}{R_1}+\frac{1}{R_2}$

Here $3\Omega$ and $6\Omega$ are in parallel combination: 

So, $\frac{1}{R^{\iota }}=\frac{1}{4}+\frac{1}{4}=\frac{2}{4}=\frac{1}{2}$

$R^{\text{'}}=2\Omega$

Now $R^{\text{'}}$ and $2\Omega$ will be in series combination:

Equivalent resistance,

$\left(R\right)=2+2=4\Omega$

Hence option 2 is correct.