Answer:
A) partial productivity
Step-by-step explanation:
partial productivity refers to smaller parts of company operations that can be used as a standard of measurement to gauge company's productivity as a whole.
in the example above, Brian examine the number of tungsten filaments.
Even though number of tungsten filaments alone cannot be used to measure company's productivity as a whole, higher number of tungsten filaments usually correlate with finished products that can be sold to the customers. Which means that this smaller part of company's operation can be used to gauge company's overall productivity.