In the Standard Model of a Monopoly Union Bargaining with the Firm

In the standard model of a monopoly union bargaining with the firm, it is typically assumed that

A) the union's sole objective is to increase the wage.
B) union leadership disregards the preferences of the rank and file.
C) unions never lead to an efficiency loss.
D) unions are willing to trade off some amount of employment for higher earnings.
E) unions and management secretly negotiate on the behalf of stockholders.