As you read the lines below, use your knowledge of Latin and Greek roots to determine the meaning of any unfamiliar words. Ador'd for ever be the God unseen,
Which round the sun revolves this vast machine,
Though to his eye its mass a point appears:
Ador'd the God that whirls surrounding spheres,
Which first ordain'd that mighty Sol should reign
The peerless monarch of th' ethereal train:

Based on your understanding of its meaning, select the root of the word ethereal.
A) Old English ǣther, "one or the other"
B) -ial, "of or related to"
C) Greek aither, "upper air"
D) Latin dies, "day"