Answer:
Bonding property
Step-by-step explanation:
Distillation deals with boiling solutions. Therefore the boiling point has a major part to play. Boiling point of a substance deals with the type of bonds present. For example water has hydrogen bonding which is a weak intermolecular force therefore the boiling point of water isn't that high. If we were to focus on an ionic compounds the boiling point would be higher because ionic compounds have ionic bonding which are stronger bonds which therefore requires more energy to break those bonds therefore a higher boiling point.
In this case for the ethanol to distill the property it's focusses on is the bonds. The strength of the bonds really.