What is the number of molecular layers on the adsorbent in chemical adsorption?

Which among the following is an example of sorption?

Methylene blue,from its aqueous solution,is adsorbed on activated charcoal at $25 \ ^{\circ}C$. For this process,the correct statement is

What are the factors which influence the adsorption of a gas on a solid?

The number of incorrect statement/s from the following is/are:
$A.$ Water vapours are adsorbed by anhydrous calcium chloride.
$B.$ There is a decrease in surface energy during adsorption.
$C.$ As the adsorption proceeds,$\Delta H$ becomes more and more negative.
$D.$ Adsorption is accompanied by decrease in entropy of the system.

Four gases $A$,$B$,$C$,and $D$ have critical temperatures $5.3 \ K$,$33.2 \ K$,$126.0 \ K$,and $154.3 \ K$ respectively. For their adsorption on a fixed amount of charcoal,the correct order is: