The mixture of compounds $A$ and $B$ is passed through a column of $Al_2O_3$ by using alcohol as eluant. Compound $A$ is eluted in preference to compound $B$. Which of the compounds $A$ or $B$ is more readily adsorbed on the column?

• A
  $A$
• B
  $B$
• C
  Both $A$ and $B$ are adsorbed equally
• D
  Neither $A$ nor $B$ is adsorbed