Striking Union Members of ABC Company Decide That Picketing ABC

Striking union members of ABC Company decide that picketing ABC Company is not accomplishing the desired results and decide to further their efforts.Sally,the union president suggests that they picket XYZ Company,a supplier to ABC,to pressure XYZ into not doing business with ABC.Which of the following is true regarding Sally's plan?

A) Sally's plan is a good idea, and this type of picketing is frequently and legally engaged in by union members during labor disputes.
B) Sally's plan is a good idea only if the strike has been going on for over 30 days because under the National Labor Relations Act, union members may not picket any company other than the employer for at least 30 days.
C) Sally's plan is a good idea only if the strike has been going on for over 90 days because under the National Labor Relations Act, union members may not picket any company other than the employer for at least 90 days.
D) Sally's plan is legal only if XYZ employees are represented by the same union as ABC employees.
E) Sally's plan is illegal because of the prohibition against secondary boycotts occurring during a labor dispute.