Which of the following graph is correctly represented according to...

According to Freundlich adsorption isotherm,
$x / m = k \times P\dfrac{1}{n}$
where, $x =$ mass of gas adsorbed on mass '$m$' of the absorbent at pressure $p$.

$k$ and $n =$ constants.

Taking logarithm on both sides, we get
$\log x / m = logk + \dfrac{1}{n}logp$

This is equation of a straight line with slope of $\dfrac{1}{n}$ and intercept of $logk$.