The diagram below shows a group of water molecules.
the water molecules in the diagram are attracted to each other
a: ionic bonds
b: hydrogen bonds
c: london dispersion forces
d: dipole-induced dipole interactions

B: Hydrogen bonds

Explanation: Hydrogen bond is a bond formed between a hydrogen atom and a electronegative atom such as fluorine, oxygen or nitrogen. It is a strong bond.

Ionic bond is formed by the transfer of electrons between metals and non metals.

London dispersion force is a temporary attractive force that results when the electrons in adjacent atoms occupy positions that make the atoms form temporary dipoles.

Dipole induced dipole interactions is a weak attraction that results when a polar molecule induces a dipole in a neighboring atom or a non polar molecule by disturbing the arrangement of electrons.

as the atomic numbers of the elements in column iia increase, the size of the atoms generally: increase stay the same- a.