challenge: Who was the father of John de Ferrers, 4th Baron Ferrers of Chartley?
  
  A. Robert de Ferrers, 3rd Baron Ferrers of Chartley
  B. John de Ferrers, 2nd Baron Ferrers of Chartley
  C. Edward de Ferrers, 1st Baron Ferrers of Chartley
  D. William de Ferrers, 2nd Baron Ferrers of Wemme
  Answer: 