The author of this passage is probably a ______.

A．how to make the workers more productive
B．possible factors leading to greater efficiency
C．to a certain extent more money lead to greater productivity
D．how to make workers' jobs more interesting

A．To make jobs more varied.
B．To give the worker freedom to do his job in his own way.
C．Degree of work contribution.
D．Demands for longer working hours.