Which of the Following Scenarios Would Be an Example of What

Which of the following scenarios would be an example of what C. Wright Mills had in mind when he said that unions were "managers of discontent?"

A) Union organizers signing up members in a nonunionized workplace.
B) Union leaders trying to convince their members that a new wage offer received from their employer was not good enough.
C) Union leaders trying to convince their members to not go on strike because their collective agreement had not yet expired.
D) Leaders of one union trying to encourage members of another union to leave that union and join theirs.