Answer:
The best choice is option A. A section is a history textbook covering the Freedom Riders.
Explanation:
Option B shows proof of the Riders and their protests and was taken at the time they were protesting, this is primary source. Option C is primary as well as it gives us a firsthand experience of the Riders's experience since he is writing to his brother. Option D is primary too because the news covered interviews from actual Freedom fighters. So this leaves us with option A, which is a secondary source as the textbook is written by people who researched and compiled information on the Riders' protests.
