What does Tiresias indicate is affecting the birds and their omens?

Tiresias, the blind prophet in "Antigone," indicates that the degradation of the city and its moral state is affecting the birds and their omens. This reflects the larger theme in Sophocles’ work, where the natural world reflects the consequences of human actions and decisions. When the city is defiled and chaotic, it disrupts the harmony of nature, leading to ominous signs among the birds. This connection emphasizes the profound impact of human behavior on the environment and suggests that the turmoil within Thebes is not just a political or social issue, but one that resonates throughout the natural world.

The other options point to different scenarios unrelated to the central theme of moral corruption and chaos impacting the natural order. The focus in Tiresias' warning is on the idea that the birds’ disturbed behavior signifies deeper problems in the city itself, aligning with the overarching message of the play concerning the consequences of defying divine law.