What should farmers do to construct the sandy fields?

A、They need to plow, fertilize, level and compact a flat land.
B、They should evenly spread the thick layer of pebbles, crushed rocks or red sand
over the soil surface.
C、They should dig holes through the sandy layer into the soil for about 2 cm in depth and put seeds down in those holes.
D、They should cover the seeds with the sandy layer.