Final answer:
The pendant mask from Benin in the 18th century was cast in bronze or brass using the lost-wax casting method.
Step-by-step explanation:
In the 18th century, the form of the pendant mask from Benin was 2) Cast bronze/brass. These masks were made with intricate sculptures and were often worn by high-level chiefs and elites as a sign of loyalty to the king. The bronze masks were created using the lost-wax casting method, which involved covering a clay mold with beeswax and then encasing it in layers of clay before pouring molten bronze into the mold.