The occurrence of parallel scratches on bedrock in a U-shaped valley
indicates that the area has most likely been eroded by
a stream

O a glacier
O waves
O wind

Respuesta :

Answer:

A glacier

Explanation:

This is because glaciers lead to erosion by the process of blocking and abrasion thereby leading to deposits of it's sediments after it melts and constantly refreeze again. It deposit it sediments in an unsorted piles. It's deposit are sorted