Which detail supports the central idea that Achilles considered himself immortal?
O Styx is a river in the underworld.
O Achilles was Thetis's son.
O Sacred water would protect him.

Explanation:

Clearly sacred water would protect him.

The water in the Styx River was magical and he would be protected it.

the primary theme of "elegy written in a country churchyard" is a reflection about the significance of the lives of a group of modest people buried in a rural church cemetery. elegies focus on the death of an individual or group of people, and they generally have a melancholy tone. hope this you all.

i think the answer is d.