A Meandering River Is Flowing in a Broad, Alluvial Valley

A meandering river is flowing in a broad, alluvial valley and the river is silt- laden but also moves sand and a small amount of gravel. The government decides to build a dam across the valley for power and flood control. What will happen to the river downstream of the dam?

A) The river will not change.
B) The trapping of silt in the reservoir will change the river to a braided stream because it will only have sand and gravel in its sediment load.
C) The river will respond to the new temporary base level and cut laterally outside its valley, widening the valley.
D) The river will start to deposit sand and gravel, frequently spilling out of its channel.