What Is Crop Rotation

What is crop rotation?

A) changing the crops grown in a field from year to year
B) planting crops in rows, with close-growing plants alternating with widely spaced ones
C) using special machinery to plant crops in the previous season's residue with minimal disturbance to the land
D) leveling off slopes in staircase-like steps to prevent water from running down it
E) all of the above