Adsorption of a gas follows Freundlich adsorption isotherm. If $$x$$ is the mass of the gas adsorbed on mass $$m$$ of the adsorbent, the correct plot of $$\frac{x}{m}$$ versus $$p$$ is:

To identify the correct plot, we use the Freundlich adsorption isotherm, which describes the relationship between the amount of gas adsorbed and the pressure of the gas at a constant temperature.

The Freundlich adsorption isotherm is represented by

$$\frac{x}{m} = k,p^{1/n},$$

where $$\frac{x}{m}$$ is the amount of gas adsorbed per unit mass of the adsorbent, $$p$$ is the pressure of the gas, and $$k$$ and $$n$$ are constants that depend on the nature of the adsorbent and the temperature.

Physical adsorption is an exothermic process. According to Le Chatelier's principle, increasing the temperature decreases the extent of adsorption. Therefore, at a fixed pressure, the amount of gas adsorbed follows the order

$$\text{Adsorption at }200\text{ K} > 250\text{ K} > 270\text{ K}.$$

The Freundlich equation also shows that the relationship between $$\frac{x}{m}$$ and $$p$$ is non-linear, since $$0 < \frac{1}{n} < 1$$. Thus, the graph should be a curve that rises with increasing pressure and gradually levels off rather than a straight line. This eliminates options (B) and (D).

Among the remaining curved plots, the correct graph must also satisfy the temperature dependence, with the curve for $$200\text{ K}$$ lying above those for $$250\text{ K}$$ and $$270\text{ K}$$. Plot (A) correctly represents both the Freundlich adsorption isotherm and the effect of temperature on adsorption.

Hence, the correct answer is Option (A).