Answer:
B. gold
Step-by-step explanation:
Great Zimbabwe was a major city near Lake Mutirikwe and the town of Masvingo. The city was the capital of the Kingdom of Zimbabwe. The ruins are a World Heritage site by UNESCO.
The main source of wealth of Great Zimbabwe was gold, and to a lesser extent, ivory. More than 20 million ounces of gold were extracted from the ground. The trade expanded as far as China.