Sandstone Is a Much More Common Reservoir Rock for Petroleum

Sandstone is a much more common reservoir rock for petroleum than shale because__________ .

A) shale is more porous so the oil tends to leak out over time
B) shales, especially black shales, are much richer in primary organic matter than are sandstones
C) sandstone is more abundant than shale
D) sandstones are more permeable than shales so subsurface flows of fluids tend to be directed through sandstone strata rather than through shales