In the Short Run, Why Does a Production Function Eventually

Multiple Choice

In the short run, why does a production function eventually display diminishing returns to labour?

A) As the number of workers increases, it becomes difficult to monitor them.
B) As a firm hires more workers, the skills and the work ethic of the additional workers will eventually decline.
C) As the number of workers increases, eventually the gains from the division of labour and specialisation are used up.
D) The opportunity cost of hiring additional workers must eventually rise.