Lowering a stream’s base level will cause the stream to
meander
change course
deposit sediment
downcut

C. sediments deposition.

Explanation:

As te the ultimate base level is referred to as the Sea or the ocean is considered as the grand base level. Base level specifies the limit or the level till which the river can go on eroding its base It considered as an imaginary level. So when the base level is eroded or reduced the cause the stream to broaden and deposit its sediments load downwards.

downcut

Explanation:

Lowering a stream base level is likely to downcut the stream, whereas raising the base level is likely to deposit the material along with the flowing water in the channel.

When a stream has cut the channel closer to the base level, the energy is directed from side to side and erosion produces a flat valley in the floor or floodplain.

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b.

developed countries have tended to improve the environment, while developing countries have tended to damage it.