The phrase sword-feast is a kenning. Option B is correct.
A kenning is a type of circumlocution which adopts the form of a compound that usess figurative language in place of a more concrete single-word noun. Kennings consist of two words, and are usually joined by a hyphen. An example of kenning, in addition to the one provided in the phrase above may be whale-road.
So, as sword-feast is hyphenated, it is a kenning.
