The answer to your question would be that the choice that shows the proper way to use a semicolon is the following one: In the night sky is not very realistic; nevertheless, it is beautiful. That is, the correct option is D.
You should use semicolons with conjunctive adverbs. When you have a conjunctive adverb linking two independent clauses, you should use a semicolon. In this case, the conjunctive adverb is linking the clauses "the night sky is not very realistic" and "it is beautiful".