The satellite image above shows a portion of the namib desert in africa. this is an ancient, sandy desert with dunes that can be up to 305 m tall. the namib desert extends inland from the atlantic ocean between 80 km and 200 km and receives only 5 mm to 76 mm of rain each year.
a satellite picture of this same area taken weeks before shows that the shape and location of some sand dunes have changed. which of these most likely caused the changes in the dunes?

a) ocean waves
b) flowing rivers
c) blowing wind
d) crustal uplift