Answered

In Morte d'Arthur, what does Sir Gawain tell King Arthur in a dream?

AKing Arthur will be killed if he fights Mordred the next day.
BSir Lancelot is coming to join Mordred in fighting King Arthur.
CKing Arthur should not trust Sir Bedivere with his sword.
DMordred will pretend to agree to peace and then attack.

Verified Answer :

I believe that: Sir Gawain tells King Arthur that "King Arthur will be killed if he fights Mordred the next day" A)

The correct answer is A.

After being mortally injured, Gawain writes to Lancelot, asking for his help against Mordred.

He then appears in the King's dreams, warning him to not fight and wait for Lancelot's return to Britain to attack Mordred.