Answer:
U-shaped river
Step-by-step explanation:
If the option was available to choose from one of the two then the better option would probably be a U-shaped river. This is because these rivers are formed by Glacier movement, meaning that the glaciers themselves create the U-shape and later begin to melt which fills the path made and creates the river. This leads to the water being much cleaner than V-shaped rivers. V-shaped rivers on the other hand are created from erosion caused by the river itself.