Concept:All farm power sources lose efficiency with constant use due to fatigue, wear, or depreciation.
Explanation:Constant use causes farm power sources to become less efficient over time.
Human labour gets tired and cannot sustain maximum output.
Animal power also suffers from fatigue and reduced working capacity.
Mechanical power machines undergo wear and tear, leading to reduced performance.
In the diagrams, sources I, II and III all represent forms of farm power that are affected by continuous use.
Therefore, the efficiency of all three illustrated sources decreases when used constantly.
They all need rest, maintenance, or replacement to restore their effectiveness.
Thus, the correct option is the one that states I, II and III.
Answer:D. I, II and III
