What is the basic difference between the definitions of Labor Relations and Employee Relations?

Question $8$ Answer

a$.$

Labor Relations generally pertains to a unionized environment while Employee Relations usually refers to a nonunion environment.

b$.$

There is no difference.

c$.$

They are both obsolete and have been replaced by the term Human Resources

d$.$

Employee Relations covers the full spectrum of human resource functions, while Labor Relations only pertains to a unionized work environment.