Answer: E.) Even if the Athenians were shown to be an artistic people, that designation should not be extended to all peoples of ancient Greece.
Explanation: The author emphasizes that Athens was just one among many ancient Greek cities in order to dismiss the idea that the Athenians’ reputation as an artistic people should be extended to “the Greeks” in general. By modifying “Athenians” with this phrase, the author is able to limit the scope of his argument: since he presents the Athenians as the only possible candidate for an “artistic people” in ancient Greece, he can focus solely on analyzing the Athenians without having to consider people from other Greek cities.