Answer:
B 3 lithlums
Step-by-step explanation:
The charge on a Nitrogen ion is always -3.
Nitrogen has an oxidation state of -3 and it implies that it must gain or share three electrons in order to be stable.
Since lithium has an oxidation state of +1, it implies that it will lose one electron to be stable.
Therefore, force every nitrogen atom, we are going to need three lithiums to create a balanced and complete bond specie.