Which kind of union involves workers of a particular trade or occupation?

A. craft union

B. industrial union

C. public employee union

D. trade union

Labour Unions in Canada, organizations that represent Canadian workers in their negotiations with employers. Labour unions engage in collective bargaining with employers to determine issues such as wages, the terms and conditions of work, and worker security. Unions also engage in political activities on behalf of workers and have historically had ties to political parties, such as the New Democratic Party (NDP). At the beginning of the 21st century nearly 4.2 million workers in Canada belonged to a union, or about one quarter of the country’s workforce.