Moraines Are Composed of Jumbled Piles of Very Poorly Sorted

Moraines are composed of jumbled piles of very poorly sorted rock fragments ranging in size from boulder to clay that fall out near the edges of glaciers.Why are the larger particles (boulders,etc.) not broken down during transport in the glacier?

A) because the ice is not strong enough to break up rock
B) because sediments are picked up and carried along with the ice as it moves
C) because the sediments are not carried for very long distances
D) because the ice stops the chemical weathering processes