Which of the following actions of a labor organization would be regarded as an unfair labor practice as per Section 8(b) of the National Labor Relations Act (NLRA)?

A. attempting to induce an employer to engage in secondary boycott activities

B. refuse to bargain collectively with a duly certified representative of the employees

C. assisting with the formation of any labor organization, including contributing financial support to it

D. allow employees to become provisional union members and then charge them premium dues