Plant closings, refusing to hire pro-union applicants, firing or harassing union supporters and using permanent strike replacements are all examples of:

A) Participatory management.
B) Adversarial HR management.
C) Union suppression.
D) Union substitution.

These are all tactics used by employers to suppress union formation and activity in the workplace. Participatory management involves involving employees in decision-making and is not related to union activity. Adversarial HR management can refer to any situation where the interests of management and employees are in conflict, but does not specifically relate to unions. Union substitution refers to management creating alternative employee organizations, which is not mentioned in the given scenario.