King believes that freedom…

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.

the answer is: shift

the shift is a rhetorical technique that allows the author to change the mood of the writing, go from a expository mode to a descriptive, or from narrative to persuasive, for example, can be also the change of focus or the comparation along two different time set, this can be notice in this except along the comparation and change of focus made by sotomayor.