Concept:Labour is a human factor of production whose features include active participation, mobility, and earning wages or salaries.
Explanation:Labour is an active factor because it requires human effort and involvement.
It is considered highly mobile because workers can move between jobs, occupations, and places.
The reward for labour is wages or salaries paid for work done.
However, the efficiency of labour does not depend only on its size or number of workers.
Efficiency depends on factors such as skill, training, experience, health, and motivation.
Thus, saying that its efficiency depends on its size is not a correct feature of labour.
Answer:D. Its efficiency depends on its size.