The correct answers are:
<em>C) glaciers;</em>
<em>D) rivers;</em>
The glaciers, with their massiveness, sheer force and weight, are able to break down both, big and small parts of the rocks, thus eroding them. Considering that the glaciers are also moving, though slowly, they are transporting the eroded material over shorter or longer distance, depending on the length of the glacier itself.
The rivers, with their force and also with their chemical composition, manage to erode the rocks little by little, and than transport the eroded sediment. The transportation distance depends on the length of the river, as well as its speed.