Read the passage below carefully and answer the question that follows:
For centuries, the Uburu Salt Lake in Ebonyi State, Nigeria, has served as a vital centre for traditional salt production. Unlike industrial salt mining that relies on underground shaft drilling, Uburu salt is harvested through an evaporating process using natural brine springs. Women in the Uburu community traditionally lead this craft, funneling the saline water through sun-baked clay mounds known as 'mparata' to filter out heavy silt before boiling the concentrated liquid in earthenware pots. Historical records indicate that during the Nigerian Civil War from 1967 to 1970, Uburu became the chief supplier of essential sodium chloride to the blockaded Eastern enclave when maritime imports ceased. Today, despite competition from refined table salt, Uburu salt remains culturally significant, though production yields have declined due to seasonal flooding of the brine springs.
According to the passage, what specific function do the 'mparata' clay mounds serve in the traditional salt extraction process?
- Filtering out heavy silt from the saline water prior to boilingCevap
- BBoiling the concentrated saline liquid to crystallize sodium chloride
- CDrilling underground shafts to reach natural brine spring deposits
- DShielding the natural brine springs from seasonal flooding