Mining is important to the economy of Ethiopia as a diversification from agriculture. Currently, mining comprises only 1% of GDP. Gold, gemstones (diamonds and sapphires), and industrial minerals are important commodities for the country's export-oriented growth strategy. Tantalum mining has also been profitable.
I think the answer is E. A great thickness of sedimentary rocks exists in Death-Valley-type faulted basins, which can be seen deep in the canyon in many places.
