Which One of the Following Best Describes the Geology of the Black

Multiple Choice

Which one of the following best describes the geology of the Black Hills region in South Dakota?

A) a large graben deeply eroded by Pleistocene glaciers
B) an elongate upwarped dome between the Cheyenne and Belle Fourche Rivers, flanked by hogbacks of the Dakota Sandstone and cored by older crystalline igneous and metamorphic rocks
C) an eroded syncline with Cretaceous and Tertiary younger, sedimentary strata in the axial region, and older, metamorphic rocks around the margins
D) a basin filled with folded, sedimentary rocks and thick Precambrian coal beds