The correct answer is “Dr. King uses metaphors in his "I Have a Dream Speech" to communicate complex ideas”. Figurative language makes use of figures of speech to be more effective and persuasive. These figures of speech could be metaphors, similes or allusions. A thesis statement for an essay that analyzes figurative language should state key points considered for making such analysis. In this case, the best example of such thesis statement is the one that reads “Dr. King uses metaphors in his "I Have a Dream Speech" to communicate complex ideas”, since one can spot that a key concept related to figurative language is in this thesis statement: metaphors. The rest of the options does not mention key concepts related to the topic that will be developed in the essay (figurative language).