Arthur is A- mortally wounded. This is the correct option.
Arthur is betrayed by his son Mordred. Mordred names himself king of England while his father, Arthur, is away in France. Arthur comes back to England when he learns about his son's treason. In England, they meet in single combat and Arthur gets wounded in the head.
B. CROWNED KING OF ENGLAND . Arthur dies before he can become KIng.
C. BETRAYED BY LANCELOT . This is not why Arthur meets his son in single battle. Lancelot is in France.
D. CHASTISED BY MERLIN. Merlin, the wizard, is Arthur's friend.