What pairs does the second substance have the lower boiling point in?

I feel that the answer is incorrect - it should be H2S and H2O.

H2S is a gaseous and polar molecule - it is held together by dipole-dipole interactions between the hydrogen and sulfur atoms. Dipole-dipole interactions are relatively weak in comparison to the intermolecular forcers that exist in water molecules (H2O) - thus, H2S has a lower boiling point than H2O.

H2O on the other hand is a polar liquid and solvent. It is held together by hydrogen bonds, a type of dipole-dipole interaction that is very strong. As such, a large amount of energy is required to break the hydrogen bonds between the H2O molecules, giving H2O a high boiling point (100 degrees celsius).