Final answer:
The correct answer is stichomythia, which is a form of dialogue that alternates single lines between characters in a play by Aeschylus.
Step-by-step explanation:
The dialogue in Aeschylus' plays could be in the form of agon or stichomythia. Agon is a structured debate where two characters argue opposing viewpoints, often with complex speech. On the other hand, stichomythia is a technique that involves a rapid exchange of single lines or short passages by two characters. This technique often heightens the drama and tension during a conflict in the narrative.
Given the definitions, the dialogue form that alternates single lines between characters is stichomythia. So, in response to the question, the correct answer is 2) Stichomythia.