The line "The ancient dawn-flier's,|| vessels a-standing" exemplifies the characteristic of a kenning in epic poetry. A kenning is a type of metaphorical compound expression used in Old English and Old Norse poetry to create a vivid image by combining two or more words in a metaphorical way.
In this line, "The ancient dawn-flier's" is a kenning for a bird, which paints a picture of an ancient bird that flies at dawn. The use of kenning adds depth and richness to the description by using metaphorical language to convey the characteristics or attributes of the subject in a creative and imaginative manner.
Therefore, the correct answer is:
C. kenning
