Final answer:
Mentor texts in an instructional program primarily benefit students by showing them exemplar (B) writing to emulate, specifically through word choice, text structure, and point of view.
Step-by-step explanation:
The primary benefit of including mentor texts in an instructional program to develop students' writing abilities is demonstrating to pupils how an author uses features like word choice, text organization, and point of view to communicate ideas in ways that they may imitate. Mentor texts serve as models for students, illustrating how effective writing is structured and crafted.
By examining the mentor texts, students can observe the nuances of language and rhetorical strategies used by experienced writers and apply these techniques to their own writing. This process does not only improve their writing skills but also helps them in developing critical reading skills, as they learn to notice the stylistic and organizational choices that make texts effective.