challenge: What was happening to vintage rock 'n' roll in the early '70s, according to the liner notes to the 2006 compilation A Half Century of Hits?
  
  A. It was being forgotten, with many of its original artists retiring from the music industry
  B. It was being replaced by a new genre of music that combined rock and country elements
  C. It was declining in popularity due to the rise of country music
  D. It was experiencing a rebirth, with a renewed interest in the original rock and roll spirit
  Answer: 