Read the passage below carefully and answer the question that follows:
Constructed around 800–1000 AD in honor of the noblewoman Oloye Bilikisu Sungbo, Sungbo's Eredo is a massive system of defensive ramparts and ditches located in southwestern Nigeria. Spanning over 160 kilometers, the earthwork enclosure encompasses a total area larger than modern Greater London. Unlike European stone fortresses of the same era, the Eredo was built entirely from compacted laterite soil and weathered clay without mortar or stone reinforcement. Excavations reveal that its vertical ditches reached depths of 20 meters, designed to absorb rainwater rather than retain water moats. The primary economic function of the inner precincts was to regulate regional ivory and salt trade routes rather than serve as a permanent agrarian settlement.
According to the passage, which of the following statements is explicitly true regarding Sungbo's Eredo?
- Its vertical ditches were engineered to absorb rainwater rather than serve as water-filled moats.Cevap
- BIt was built using mortar-bound stone reinforcement influenced by European architectural designs.
- CThe inner precincts served primarily as a permanent agrarian settlement for surrounding farming communities.
- DThe earthwork structure was designed as a water storage reservoir to sustain local livestock during droughts.