Answer:
C a talus slope
Step-by-step explanation:
A rockfall consists of rock falling down steep slopes and cliffs.
The rock fragments found at the feet of the slopes are called talus or a talus slope.
A is wrong. A delta is formed from the sediment carried by a river.
B is wrong. A sand dune is a hill of loose sand formed by the action of wind or water.
D is wrong. An alluvial fan is a triangle-shaped deposit of water-transported gravel, sand, and silt.