Hiya!
The answer to your question is B.
The first shell only holds 2 electrons so the 3rd electron had to go in the second shell
Step-by-step explanation:
The first shell can only hold a maximum of 2 electrons, the third electron must go into the second shell. Therefore the lithium, which has three total electrons, will have two electrons in the first shell and one electron in the second shell.
~Hope this answers your question!~