Concept:Boiling point depends on the strength of intermolecular forces.
Explanation:Option A has two
−OH groups, so it can form many intermolecular hydrogen bonds.
Stronger hydrogen bonding requires more energy to separate molecules, giving a higher boiling point.
Options B and C are alkyl bromides, which show only dipole-dipole and van der Waals forces, not hydrogen bonding.
Option D has one
−OH group but is branched, which reduces surface area and hydrogen bonding.
Therefore, option A has the strongest intermolecular attraction.
Answer:Option A:
CH3−CH(OH)−CH2−CH2−OH