By increasing the amount of an adsorbate, the extent of interaction between adsorbate and adsorbent also increase. Therefore, option (i) is correct.

Decrease in surface area of adsorbent decrease the rate of adsorption.so (ii) is wrong.

If the temperature of solution increase, then gas may escape from the solution which results the decrease in rate of adsorption. So (ii) is also an incorrect option.

Decrease in amount of adsorbate in solution will decrease the extent of adsorption. So (iv) is wrong.