Final answer:
The hip-hop groups aimed at the mainstream and considered less authentic by some critics were Salt-N-Pepa and DJ Jazzy Jeff & The Fresh Prince. These groups faced backlash for their more commercial approach, which contrasted with the politically charged content of groups like Public Enemy.
Step-by-step explanation:
The two hip-hop groups that were aimed at the mainstream and faced backlash for not being authentic enough are c) Salt-N-Pepa and DJ Jazzy Jeff & The Fresh Prince. These groups were criticized for their more approachable and less politically charged content compared to other hip-hop acts of the time. Mainstream success led some to view their music as less reflective of the true essence of hip-hop culture, which often revolved around political issues and the struggles of inner-city life. Notable exceptions to this critique would be groups like Public Enemy, who utilized their platform to confront issues such as racism with politically charged lyrics in songs like "Fight the Power". The rise of hip-hop into mainstream culture was partially attributed to the contagious diffusion, where styles and influences spread from inner cities to small towns, resembling the pattern seen in the spread of contagious diseases.