It would be the labor’s first step in solving labor problems and effecting change.

a.) striking
b.) collective bargaining
c.) protest marching
d.) joining a union

B). Collective Bargaining.

Explanation:

'Collective Bargaining' is stated as the title suggests the course of negotiation or bargaining amid the employer and the workers' union on the 'terms and conditions of employment'. These terms are likely to include the concerns of the workers/labors working in the industry suffers and the agreements on an appraisal of payment, the work conditions or compensations and benefits regarding the rights of the workers, etc.

As per the question, the first and initial step to solving the labor problems and influencing change would be 'collective bargaining' that would help negotiate with the employer considering their(labors') wages and rights. If the employer denies agreeing with the terms, then only any further step must be taken to resolve the problems. Therefore, option B is the correct answer.

answer; (d) all of the above; 100%