The correct option is
D All of the above
Tillage is the agricultural preparation of soil by mechanical agitation of various types, such as digging, stirring, and overturning. The purpose of tillage is multi-fold. Tillage serves to
(i) Reduce soil compaction from roads and/or heavy construction equipment,
(ii) Remove unwanted vegetation (weeds),
(iii) Prepare a seedbed,
(iv) Dilute surface contamination below an appropriate action level,
(v) Incorporate fertilizer, and
(v) Stabilize the soil by removing erosion features such as rills.