Why is each of the following good legal advice?

a. When using independent contractors, firms must be prepared to relinquish most of their control over how work is done.

b. Firms should closely review the status of long-term independent contractors and not assign new projects to them without renewing agreements.

c. Independent contractor agreements should be used, but only when they document actual independent contractor relationships.

d. Be particularly cautious about changing the status of workers from employees to contingent workers or having workers with different statuses perform the same work for long periods of time.

e. Client companies should refrain from closely supervising agency temporary workers or selecting individual temp workers for hiring or firing.