The nazis most likely used the death marches to

a - punish camp prisoners for uprisings.
b - move prisoners from one camp to another.
c - move jews from ghettos to concentration camps.
d - hide the proof of the holocaust.

They used death marches in order to hide the proof that the Holocaust happened or at least that it wasn't as bad as it was. In 1945 the Germans were decisively losing the war so the SS organized the so-called death marches. They were most likely called death marches by the prisoners and not the SS. They evacuated the camps to keep prisoners from getting liberated.

d)to gain support for the independence movement.

hope this : )

he died and left a legacy that will never be i think