Match the procedural step to its purpose by dragging each step in the written procedure for the aldol condensation of dibenzyl ketone and benzil in ethanol solution in the presence of potassium hydroxide base, followed by the UV analysis of the product in hexane solution.

A) reaction flask heated under reflux on a steam bath
B) greased all ground glass joints prior to heating under reflux
C) obtained uv spectrum within 30 seconds of preparing the solution.
D) The hydroxide pellets were dissolved in absolute ethanol.