The correct answer is A. silting river.
An aggrading river is a river that is depositing sediment, or silt, on its bed. This can happen for a number of reasons, such as a decrease in the river’s velocity, an increase in the amount of sediment being carried by the river, or a change in the river’s course. Aggrading rivers can cause problems for humans, as they can lead to flooding, erosion, and the loss of land.
A scouring river is a river that is eroding its bed. This can happen for a number of reasons, such as an increase in the river’s velocity, a decrease in the amount of sediment being carried by the river, or a change in the river’s course. Scouring rivers can also cause problems for humans, as they can lead to flooding, erosion, and the loss of land.
A river that is both silting and scouring is a dynamic river. This type of river is constantly changing its course and shape. Dynamic rivers can be dangerous, as they can be unpredictable.
A river that is neither silting nor scouring is a stable river. This type of river has a relatively constant course and shape. Stable rivers are usually less dangerous than dynamic rivers.