Hey! In this question, we are actually comparing the intermolecular forces present in each compound with its boiling point. The stronger the intermolecular force of a compound, the higher the boiling point.
For our first compound we have formic acid. Here we have an OH present, meaning that hydrogen bonding is an intermolecular force present.
For ethanediol, we have two OH's present, meaning more hydrogen bonding than formic acid.
Dichloromethane has no hydrogen bonding, so its intermolecular forces are weaker.
Because our compound with the strongest intermolecular force is ethanediol since it has hydrogen bonding in two different places, we are going to say that it is going to have the highest boiling point, in this case being 197.3 degrees C. Next, we will have formic acid, since it also still has hydrogen bonding, so the boiling point will be 101.0 degrees C. Finally, we will have dichloromethane with the lowest boiling point, simply because it has the weakest intermolecular forces, giving it a boiling point of 40 degrees C. Hope that helped!