An author of a technical manual would use to make numerical data easier for the reader grasp

it is the : d because is true

the right answer is b

beowulf is filled with alliterations, caesuras, and kennings intended both to give the epic a musical, rhythmic quality and to assist the bard performing the epic in remembering the lines. just as the lyrics to our favorite songs are easier to remember than a context-free list of names or census data, poetic devices like those listed above stick in the bard's mind.

it is not known if beowulf was chanted, sung, or recited more like a modern day poem, but the poetic devices evident in the epic almost certainly had their origin in memorization and oral recitation.