Final answer:
Clytemnestra is shown to be more dominant than Aegisthus because Aegisthus defers to her decisions, indicating her higher position of power in their relationship.
Step-by-step explanation:
The question asks which aspect demonstrates that Clytemnestra is more dominant than Aegisthus in the context of classical literature. An indicator of Clytemnestra's dominance over Aegisthus is that Aegisthus defers to her decisions. This shows that Clytemnestra holds more power or authority in their relationship, as she makes critical decisions and Aegisthus follows her lead. The other options listed, such as age, voice volume, or the number of servants, do not directly relate to dominance in decision-making within classical Greek narratives.