Question

While many people assume that the Sahara Desert has always been a barren landscape, geological evidence tells a different story. Thousands of years ago, this region was a green, lush environment characterized by lakes, rivers, and diverse vegetation. Researchers studying fossilized pollen and lake sediment cores have discovered evidence of ancient monsoon cycles that once brought significant rainfall to the area. This transformation, driven by shifts in the Earth's orbit, suggests that the desert's climate is not static but changes dramatically over long, geological timeframes.
Which choice best states the main idea of the text?
A. The Sahara Desert is currently a barren landscape that was once filled with, in some areas, lakes and rivers.
B. Researchers are using pollen and sediment to study the history of the Sahara Desert.
C. Geological evidence indicates that the Sahara Desert was once a lush, green environment due to ancient monsoon cycles.
D. Shifts in the Earth's orbit are the sole cause of climate change in arid regions.

Answer 1

C. Geological evidence indicates that the Sahara Desert was once a lush, green environment due to ancient monsoon cycles.