Which one of the following property is generally not exhibited by ionic compound?

Ionic compounds are mainly soluble in water and form hydroxide i.e $M(O{H}^{-}{)}_n$where n is the valency of metal.

They conduct electricity in their molten state because, in a molten state, their electrons are free to move while in a solid state their electrons are not free to move and hence they are unable to conduct electricity.

Ionic compounds have high melting and boiling points.

Eg. NaCl.

Electrical conductivity in a solid state is generally not exhibited by ionic compounds.