By subtracting a measured unit productivity rate during an impacted period from the unit productivity rate during an unimpacted period, the resulting…

 Calculation of Productivity Loss:

Subtracting productivity during an impacted period from unimpacted productivity quantifies the

reduction in efficiency or loss in productivity.

 PSP Study Guide Reference:

Productivity analysis includes evaluating impacted vs. unimpacted periods to assess losses.

 Conclusion: The correct answer is C, as the difference represents productivity loss.