Answer:
a: Li₂O
Step-by-step explanation:
Ionic compounds are good conductors only in liquid state. They do not conduct electricity in their solid state.
The only ionic compound from the given choices is Li₂O.
Ionic compound do not conduct electricity in their solid state because their ions are locked and are not free to move about their fixed lattice. In liquid states, they go into solution and they are free to move thereby acting as a good conductor.