Concept:Labour is classified by the level of training and the type of effort required to perform a job.
Unskilled labour relies mainly on physical strength rather than formal education or training.
Explanation:Unskilled labour is the type of labour that depends on physical effort and energy.
It requires no special training, technical knowledge, or previous experience.
Skilled labour needs specialised training and mental ability, not just physical effort.
Semi-skilled labour requires some limited training but is not primarily based on physical strength.
Blue-collar and white-collar describe job categories, not the classification of labour by training or effort.
In production processes such as farming, loading, or digging, the workers involved mainly use unskilled labour.
Therefore, the type of labour that makes use of physical effort is unskilled labour.
Answer:A. Unskilled labour