The thing that can be said about Bob Dylan and Joan Baez during the folk revival is: c. they had top 40 albums.
What is folk revival?
Bob Dylan and Joan Baez were both significant figures in the folk music scene during the 1960s folk revival. Their concerts, activism, and creative songs made them well-known. Even while they may have had hit songs, their impact and success during that time period are better captured by the claim that they had top 40 albums.
Even though they weren't particularly well-known for creating hit songs in the traditional pop sense, their albums as a whole were well-received and accurately captured the political and cultural milieu of the era. Both musicians were influential figures in the folk revival and had a lasting impact on subsequent generations of musicians by using their music to highlight significant societal issues.
Therefore the correct option is C.