What does Antigone tell her sister outside the city gates?

The correct answer is - Antigone tells Ismene that Creon ordered a full funeral honoring Eteocles, according to their customary rites and leave Polyneices to rot with no funeral or lament.

When they are outside the city gates, both of them lament the deaths of their brothers Polyneices and Eteocles. They died fighting each other, however, one is considered a traitor (Polyneices), whereas the other one is a hero. The hero will receive a proper burial, according to Creon, whereas the traitor will not - he will just be left to rot somewhere, without a grave.

Antigone tells Ismene that Creon ordered a full funeral honoring Eteocles, according to their customary rites and leave Polyneices to rot with no funeral or lament.