On which operation on the following no plant is left undisturbed?

Explanation

In clean tillage, the soil is thoroughly cultivated, and all plant residues and weeds are completely removed. This operation disrupts the existing plant material and vegetation, leaving no plant undisturbed. In contrast, options like deep tillage, subsoiling, and year-round tillage may involve soil disturbance but do not necessarily remove all plant material, making clean tillage the operation where no plant is left undisturbed.