Final answer:
The Chorus confirms that Thebes has seven gates in the provided text excerpt.
Step-by-step explanation:
According to the Chorus in the scene, Thebes has seven gates. The line from the text, 'Our seven-gated Thebes the brightest ray, O eye of golden day,' explicitly confirms the number of gates to the city. Not only does the Chorus talk about the number, but the significance of the seven gates plays a recurring role in the context of Theban plays, especially in the context of the siege and battles that are referenced in the storyline.