ANS:D - channel flows in unlimited, incoherent alluvium of the same character as that transported material.

For true regime condition;

Discharge, silt charge, silt grade, and flow must be constant.

Also, the flow should occur through a material that can easily be scoured and deposited, say incoherent alluvium.

These are the conditions for a true regime.

Apart from that, there is the initial and final regime.

Lacy's theory is not applicable for the true regimes since the proposed criteria won't occur together in a real situation.