What country contains the largest ruins in sub-Saharan Africa?

Here is the question :

WHAT COUNTRY CONTAINS THE LARGEST RUINS IN SUB-SAHARAN AFRICA?

Here is the option for the question :

Cameroon
Lesotho
Kenya
Zimbabwe

The Answer:

And, the answer for the the question is :

Zimbabwe

Explanation:

[STC0018216]. The greatest African ruins complex south of the Sahara Desert is the Great Zimbabwe Ruins, which were constructed somewhere between the 11th and 15th centuries. Turrets and intricate staircases are only a couple of the architectural features that set this site apart from other ancient ruins of a similar nature discovered throughout the continent.