Final answer:
The correct answer is Unferth.
Step-by-step explanation:
The subject of the question is English. The question is asking about Beowulf and his childhood friend in the context of a sea match. The options provided are Grendel, Unferth, Hrothgar, and Wiglaf. Based on the context of the question, the correct answer is Unferth. Unferth was a childhood friend of Beowulf and played a significant role in the poem.