Verified answer

It all has to do with their intermolecular forces.

CH4 has the weakest, so they forces are easier to overcome therefor easier to evaporate or boil

C6H14 has a little bit stronger forces so it is easier to overcome the forces to melt, but not enough to evaporate or boil.

C2OH42 has hydrogen bonding (the strongest intermolecular force) so it is hardest to overcome the forces to melt or boil