Answer:
C. increased; increased or did not change
Step-by-step explanation:
The number of employees clearly increased. As new jobs position were filled.
Now we must understand that labor force is determinate by the employees and the people actively looking for a job position.
If during the time period all these jobs were filled with people statistically consider unemployed then, the labor force did not change.
However, if there people which weren't looking for a job are offered with a job positiion an take it this increase the labor force as they weren't count before.
Therefore, the labor force could increase or stay at the same level