challenge: Which teams competed in the World Group play-offs in the 2019 Fed Cup?
  
  A. The four winning teams in the World Group II ties
  B. The four losing teams in the World Group first round ties and the four losers of the World Group II ties
  C. The four winning teams in the World Group first round ties
  D. The four losing teams in the World Group first round ties and the four winners of the World Group II ties
  Answer: 