How does Beowulf's story about the battle with Breca differ from Unferth's version of the story?

ABeowulf told how breca was reluctant to enter the competion in the 1st place.

BBeowulf suggests that Breca's swimming abilities hindered his fighting skills.

CBeowulf says that breca lost the competio and then betrayed him.

DBeowulf explains that he fought off sea monsters all night, so he couldn't participate in the challenge with Breca.