H2O,NH3,C2H5OH⇒ Intermolecular H-Bonding
The hydrogen bonding which takes place within a molecule itself is called intramolecular hydrogen bonding.
It takes place in compounds containing two groups such that one group contains a hydrogen atom linked to an electronegative atom and the other group contains a highly electronegative atom linked to another electronegative atom of the other group.
The bond is formed between the hydrogen atoms of one group with the more electronegative atom of the other group.
So the answer is:

