Final answer:
In Sir Thomas Malory's 'Morte d'Arthur', King Arthur fights against Mordred (option B). These characters are part of the broader Arthurian legend, which also features knights like Lancelot, Galahad, and Gawain.
Step-by-step explanation:
In the epic poem Morte d'Arthur by Sir Thomas Malory, which is part of the Arthurian legend, King Arthur fights against Mordred. Mordred is Arthur's nephew and, in some versions of the tale, also his son, and he betrays Arthur by attempting to usurp his throne. During the final battle, Arthur and Mordred inflict mortal wounds upon each other. While Sir Lancelot is a central figure in the Arthurian legends, known for his affair with Queen Guinevere and his exemplary knighthood, he does not fight Arthur in this work; instead, his conflict with Arthur is more personal and less physical.
Tennyson's portrayal of the Arthurian legends in his poem also includes characters like Sir Gawain, Sir Galahad, and of course, Sir Lancelot. These knights are renowned for their adventures and deeds associated with the Round Table.