What should have warned the people of coastal Venezuela that they were in a hazardous zone?

A) the cities were built upon alluvial fans
B) the houses had been built on debris flow deposits
C) the areas above the city had steep unstable slopes
D) all of these

Alluvial Fans

Cone-shaped deposits of sediment crossed and built up by streams, typical at the base of mountain ranges in arid and semi-arid climates.

Hazardous Zone

An area that poses risks to human health, property, or the environment due to natural or human-made hazards.

Debris Flow Deposits

Accumulations of material, including rocks, soil, and vegetation, transported and deposited by fast-moving flows of water mixed with debris.