In this passage, Tennyson is using a meteor to emphasize what aspect of Lancelot?

As often through the purple night,
Below the starry clusters bright,
Some bearded meteor, trailing light,
Moves over still Shalott. (“The Lady of Shalott”; lines 96–99)
A. Bravery
B. Fighting skill
C. Handsome looks
D. Heroic nature