As an HR Professional You Should Be Familiar with the Terminology

As an HR Professional you should be familiar with the terminology, practices, and rules governing union-based strikes. What is the ally doctrine?

A) A union may expand upon its primary picketing activity to include employees who are allies of the primary employer.
B) Employers cannot force friends, colleagues, and family members into joining a union picket. Allies of the picketing union can allow allies into the picket line.
C) A union may expand upon its primary picketing activity to include employers who are allies of the primary employer.
D) A union may serve as an ally to another striking union by allowing their members to join the picket against the primary employer.