Answer:Several theories have been proposed for the formation of desert pavements. A common theory suggests they form through the gradual removal of sand, dust and other fine-grained material by the wind and intermittent rain, leaving the larger fragments behind.
Explanation: scientists have had sever theories as stated in my answer above
I believe it is the Endoplasmic Reticulum (ER).
Explanation:
A. chloroplast
B. vacuole
C. plasma membrane
D. Smooth endoplasmic reticulum