What was the cultural significance of Mary Mary's crossover success in the early 2000s, particularly regarding their ability to appeal to both gospel and mainstream audiences?

A It primarily demonstrated the increasing popularity of gospel music among white audiences. B It signaled a shift towards more overtly political themes in gospel lyrics. C It highlighted the growing acceptance of gospel themes in mainstream media and challenged conventional boundaries within the music industry. D It primarily led to a decline in the popularity of traditional gospel quartets.