The answer is: "Because the auditorium only seats 100 people,"
Subordinate clauses possess a subject and a verb, and begin with a relative clause or a subordinate conjunction, like <em>because</em>. They cannot stand as independent sentences because they do not express a complete thought. Instead, they need a to join a main clause in order to make sense. For example, "the theater mush have two showings of the movie."
