The best answer is: The use of description introduces Benjamin's interest in social justice for African Americans.
In paragraph 5, Benjamin Banneker's inclusion of a letter petitioning Thomas Jefferson for help to end slavery reflects his advocacy for social justice. The structure allows readers to understand not only his contributions to science through his almanac but also his commitment to addressing societal issues, particularly the injustices faced by African Americans. This aligns with the central idea of the passage, which highlights Banneker's multifaceted contributions to science and social reform.