Concept:Harvesters are machines used for cutting and gathering mature crops, while a plough is used for land preparation before planting.
Explanation:A plough is a primary tillage implement attached to a tractor.
It is used to break, turn, and loosen the soil for planting.
This means the plough works on the land before the crop is planted.
A mower is used to cut grass or forage crops for harvest.
A forage harvester cuts and chops forage crops in the field.
A combine harvester reaps, threshes, and cleans grain crops in one operation.
These three are all harvesting implements.
The plough, however, is not a harvesting implement because its function is soil preparation, not crop gathering.
Answer:A. Plough