Answer:
B. always increases, may increase or decrease
Explanation:
Each worker being added is going to complete some job or assemble some units hence the design capacity after addition of worker will always be greater than the design capacity before addition. But utilization = actual output * 100 / theoretical design capacity.
Hence, if actual output after addition of worker increases more in proportion than that of proportional increase in number of worker, then the utilization of workstation will increase else it is likely to decrease. If both proportion are equal then the utilization is likely to remain same.