Concept:Labour mobility refers to the movement of workers between jobs, places, or social levels.
Explanation:A change from one industry to another means the worker moves between different sectors, such as from agriculture to manufacturing.
This movement occurs at a similar level of income and status, not a change in social rank.
It is not geographical mobility because the worker may remain in the same area.
It is not vertical mobility because vertical mobility involves a rise or fall in social status.
It is not professional advancement, which means climbing to a higher position or rank.
Therefore, such a move is an example of horizontal mobility.
Answer:B. horizontal mobility.