These Pillars Are Remnants of Layers, Most of Which Have

These pillars are remnants of layers, most of which have been stripped away by wind erosion. If this occurred in less than five years you might reasonably conclude that:

A) the pillars are remnants of volcanic necks
B) this area recently has become a productive place to produce agriculture
C) there must have been drought, overgrazing, or some short-term climatic change
D) this area was originally a lake