Alluvial Terraces Form Due to Which of the Following Factors

Alluvial terraces form due to which of the following factors?

A) alluvium is deposited at different stages during gradation and so naturally occur as terraces
B) obstacles prevent the river from cutting away all of the deposited alluvium
C) overbank flooding carries debris to the outer edges of the valley so depositing the terraces
D) overbank flooding carries debris and deposits it adjacent to the river channel
E) uplift of the river channel that further entrenches meanders