The Populated Fraser River Delta South of Vancouver,B

The populated Fraser River delta south of Vancouver,B.C.,is subsiding primarily because

A) dams upstream catch the sediments that otherwise would reach the delta.
B) groundwater pumped for agriculture is causing the ground surface to sink.
C) dykes built to protect human infrastructure keep new sediments off the delta.
D) slow slippage along the Cascadia subduction zone causes the delta to warp downward.
E) sea level rise is eroding the delta faster than replenishment occurs.