The correct answer is D. Sentence 6 should be the first sentence.
Explanation
A paragraph is a piece of writing that has a central idea, also known as a topic sentence that generally is at the beginning of the paragraph. In addition, the paragraph consists of secondary sentences, which have the function of arguing, supporting, explaining, and sustaining the main idea.
According to the above, the central sentence of the text is (6) One unfortunate outcome of the Industrial Revolution was the creation of monopolies because this sentence introduces the topic and covers the central idea of the paragraph, while the other sentences argue. So the correct answer is D. Sentence 6 should be the first sentence.
