In this excerpt from Book 12 of the Odyssey, Circe advises Ulysses how to get past the Sirens unharmed. Which theme is depicted in the excerpt?

Next, where the Sirens dwells, you plough the seas;
Their song is death, and makes destruction please.
Unblest the man, whom music wins to stay
Nigh the cursed shore and listen to the lay.
No more that wretch shall view the joys of life
His blooming offspring, or his beauteous wife!
In verdant meads they sport; and wide around
Lie human bones that whiten all the ground:
The ground polluted floats with human gore,
And human carnage taints the dreadful shore
Fly swift the dangerous coast: let every ear
Be stopp'd against the song! 'tis death to hear!
Firm to the mast with chains thyself be bound,
Nor trust thy virtue to the enchanting sound.
If, mad with transport, freedom thou demand,
Be every fetter strain'd, and added band to band.

A.
loyalty
B.
overindulgence
C.
self-restraint
D.
leadership