The correct answer is c: the attraction between the H of one water molecule and the O of another water molecule.
Hydrogen bonds are weak interactions that occur when a hydrogen atom covalently bonded to an electronegative atom, like oxygen, experiences an attraction to another electronegative atom. In the case of water (H₂O), each water molecule can form hydrogen bonds with neighboring water molecules because the hydrogen atoms are partially positive and the oxygen atoms are partially negative. This unique property is crucial for many of water’s characteristics, such as its high surface tension and its ability to dissolve many substances.