Physisorption is exothermic by nature. So the rate of physisorption of a gas increases with decrease in temperature. So (ii) is correct.

With the increase in temperature gas adsorbed will escape from the surface of adsorbent. So the rate of physisorption decrease. Therefore, (i) is wrong.

The decrease in surface area of adsorbent will reduce the amount of adsorbed gas. So rate of physisorption decrease. So option (iii) is wrong.

Vander Waals forces help to adsorb a gas to the surface of the adsorbent. So with the decrease of strength of this force decreases physisorption. So (iv) is also wrong.