Answer:
A
Step-by-step explanation:
When the surface runoffs are strong enough to cause sediment detachment and if the amount of sediment is within the load limit the runoff can carry, then these conditions are set for rill erosion. The rills are the narrow shallow strips that are formed for in the wake of the runoffs. They are formed from heavy downpours. The runoffs are fast but not as fast and strong as those in gully erosion.