Final answer:
The head of an Oba is made of cast bronze and was created using the lost-wax casting technique by the Benin culture.
Step-by-step explanation:
The head of an Oba is made of cast bronze. These heads are historical artifacts associated with the Benin culture and were created through the meticulous process of lost-wax casting. This sophisticated method of bronze casting was prevalent among the Benin artists, and an Oba or a designated individual commissioned these works. The artisans created intricately detailed pieces, often portraying the Oba with a stylized, idealized youthfulness and adorned in coral beads and other ornamentations. These bronze heads were typically placed on altars to honor the Oba and were an essential part of the ritual and ceremonial activities.