$A$ mixture of three compounds $A, B, C$ is passed through a column of $Al_2O_3$ by using alcohol as eluant. The order in which they are eluted out of the column is $C, B, A$. Which of the following statements is true?

• A
  $C$ is strongly adsorbed on the adsorbent
• B
  $C$ is weakly adsorbed on the adsorbent
• C
  $A$ is weakly adsorbed on the solvent
• D
  The order of elution does not depend on the extent of adsorption