Help me answer this Earth Science question please? 10 POINTS?

[Queen Shiggedy]

I tried figuring it out and I don't know the answer.

Which characteristic exists at an erosional-depositional interface in a stream where equilibrium occurs?

1) The downstream profile is the same as the across-stream profile.
2) The rate of deposition equals the rate of erosion.
3) The rate of deposition of the sediments deposited is the same as the composition of the sediments eroded.
4) The volume of streamflow equals the volume of deposition.

[applesauce]

I not 100% sure, but number 2 is the one that make sense to me.
Erosional = seem to equal erosion (loss of soil)
depositional = seem to be deposit of soil
equilibrium = happening at an equal extent.

However I not sure about 1) I don't know what you mean by a downstream profile and a across stream profile. also 3) does seem to make much sense and 4) sound wrong since there is nothing about erosion and there was nothing about volume of stramflow.

[Theo]

2, which means that your river bank will stay not widen or shorten at all.