Answer:
Option a (worker productivity) is the correct approach.
Step-by-step explanation:
- Productivity seems to be a measure including its effectiveness of transforming inputs towards usable outputs of an individual, plant, manufacturer, or perhaps a device.
- Job efficiency seems to be a dependent variable here. The Dependent variable would be what the investigator tests during an investigation. Here, by adjusting independent factors, the investigator tests job efficiency.
All other decisions taken are also not connected to the example in the case offered. So, the solution above is indeed the right one.