What is one of the differences between the erosion of riverbeds and the erosion of glaciers?

the riverbed erodes into an l-shaped valley, whereas the glacier erodes into a w-shaped valley.
the riverbed erodes into a u-shaped valley, whereas the glacier erodes into a v-shaped valley.
the riverbed erodes into a v-shaped valley, whereas the glacier erodes into an l-shaped valley.
the riverbed erodes into a v-shaped valley, whereas the glacier erodes into a u-shaped valley.