What does the alliteration “clasps the crag with crooked hands” in the opening line draw attention to?

the eagle
by alfred lord tennyson (excerpt)

he clasps the crag with crooked hands;
close to the sun in lonely lands,
ring'd with the azure world, he stands.
the wrinkled sea beneath him crawls;
he watches from his mountain walls,
and like a thunderbolt he falls.

a) the difficulty of the bird holding onto the rock

b) the size of the rock on which the bird sits

c) the tiring body of the old bird

d) the sharp and powerful talons of the bird