Yardangs are tall, broad peaks that appear in deserts. Weathering and erosion work together to form yardangs. They are produced by the wind that carries dust or sand. The gritty wind wears away the soft rock of a cliff, leaving a shape like the one seen here. What are the agents of weathering and erosion that form yardangs?

a) wind picking up sand from the desert

b) wind and sand wearing away the rock face

c) rock particles falling to the base of the yardang

d) loose particles from the cliff blowing to new parts of the desert