Tillage can release pollutants in the soil and
increase erosion.
decrease erosion.
promote soil compaction.
promote fertilizer retention

increase erosion   (option a)

Explanation:

Increase erosion.

Explanation:

Tillage is the process of agricultural preparation of soil by digging, stirring and overturning using mechanical methods.

Advantages of Tillage:

Tillage loosens and aerates the top layer of the the soil facilitating the crop planting.

It helps mix the harvest residue, organic matter and the nutrients evenly.

Destroys the weeds mechanically.

Dries the soil before seeding (in wetter climates tillage helps in keeping the soil drier).

When done in autumn, helps exposed soil crumble over winter through frosting and defrosting, which helps prepare a smooth surface for spring planting.

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees. 

the part of the wave he is travelling on is the crest