Final answer:
The important theme in Hesiod's Theogony is the creation of the cosmos, describing the origin of the world and gods.
Step-by-step explanation:
An important theme in Hesiod's Theogony is C. the creation of the cosmos. This ancient Greek poem narrates the origins and genealogies of the Greek gods, starting with the emergence of the primordial entities and leading to the rise of the ruling Olympians. It describes a universe that emerged from chaos and was brought into order by the divine beings, illustrating the Greeks' views on the universe and the divine hierarchy that governs it. Theogony is not only a cosmological epic but also sheds light on the social structures and cultural values of ancient Greek society, reflecting their search for order and understanding of the world they inhabited.