The correct answer is C. Protest music
Step-by-step explanation:
In any text, the introductory paragraph is the first paragraph and this introduces or explains the main topic and focus in the text. Due to this, readers can know what to expect when they read the introductory paragraph. In the case presented, the author explains in the introduction many people san protest songs in multiple ways "one lone person with a guitar. They sang in segregated bus stations, picket lines, freedom marches..." and this was the way people show resistance and promoted a cause. According to this, it is likely the text is about "protest music" because the author mentions in the introduction the way people use protest music in different ways, and this is the main focus and context in the introduction rather than oppression, human rights or raising awareness.