Correct Response: D. Asking students to summarize, or write a short paragraph that describes a text's main ideas, is an informal way for teachers to assess students' understanding of a text they have read. A and C are incorrect because they focus on assessing the writing itself (e.g., using grade-level academic vocabulary and language structures correctly, organizing ideas well). B is incorrect because a summary is a not an expository text in which students take a position with respect to a text and then support their thesis with evidence from the text.