As a regular component of whole-group mathematics instruction, a fifth-grade teacher guides students in closely reading key pages from the grade-level textbook. Afterward, in addition to guiding students in applying the new material presented in the text to sample exercises, the teacher also helps the students summarize the text's main ideas orally. Finally, students draft their own written summaries of the new concepts, processes, and/or terminology in their mathematics journals. This approach to content-area instruction promotes students' school achievement primarily in which of the following ways?

A. By providing a print-rich environment in which students at all skill levels participate in differentiated literacy activities
B. By using nonverbal, concrete experiences to scaffold students' comprehension and vocabulary development
C. By promoting students' development of skill in using listening, speaking, reading, and writing for academic purposes
D. By motivating students to select a variety of informational and other nonfiction texts for independent reading