Triple

Target entity: Walter Marshal, 5th Earl of Pembroke
Context triple: [Gilbert Marshal, 4th Earl of Pembroke, successor, Walter Marshal, 5th Earl of Pembroke]

• A. Walter Marshal, 5th Earl of Pembroke chosen
  Walter Marshal, 5th Earl of Pembroke, was a 13th-century Anglo-Norman nobleman and magnate who briefly held the powerful Pembroke earldom as one of the sons and successors of the famed knight William Marshal.
• B. Gilbert Marshal, 4th Earl of Pembroke
  Gilbert Marshal, 4th Earl of Pembroke, was a 13th-century Anglo-Norman nobleman and magnate who briefly held the powerful Pembroke earldom as one of the sons and successors of the famed knight William Marshal.
• C. William de Valence, 1st Earl of Pembroke
  William de Valence, 1st Earl of Pembroke, was a prominent 13th-century Anglo-French nobleman and half-brother of King Henry III who became a powerful marcher lord in Wales and a key figure in the politics of medieval England.
• D. Richard Marshal, 3rd Earl of Pembroke
  Richard Marshal, 3rd Earl of Pembroke, was a prominent 13th-century Anglo-Norman nobleman and military leader who became one of the most powerful magnates in England and Ireland and famously rebelled against King Henry III.
• E. John Hastings, 2nd Earl of Pembroke
  John Hastings, 2nd Earl of Pembroke, was a 14th-century English nobleman and military commander who played a prominent role in the early stages of the Hundred Years' War.
• F. None of above.
• G. Unsure - the case is ambiguous/there is not enough information to decide.