Why is each of the following good legal advice?

a.Employers must not create or control "company unions."

b.Employers should not respond to union organizing efforts by raising wages or making other unscheduled changes in employment benefits.

c.Employers must abide by the terms of labor agreements when making human resource decisions regarding their unionized employees.

d.Employers should not establish informal practices of conferring benefits and privileges not specified in labor agreements.

e.If individual employees wish to present their own grievances, their union must be notified and given the opportunity to be present at any meetings about the grievances.