My sister and her friends like to make fudge when they spend the evening together 1 complex sentence 2 compound sentence 3 sentence fragment 4 simple sentence

1 complex sentence

Explanation:

A complex sentence consists of an independent clause and at least one subordinate clause. In the example sentence, the independent clause which can stand on its own is My sister and her friends like to make fudge. Meanwhile, the dependent clause which does not express a complete thought on its own is when they spend the evening together. Both clauses are joined by the subordinate conjunction when.

The rest of the options are incorrect because a simple sentence contains one clause, a compound sentence has two independent clauses, and a sentence fragment does not even form a simple clause or a complete thought.

Complex sentence is the right one