What interest group is probably most concerned with the number of hours considered a full-time work week?

Teamsters Union

National wildlife federation

American Bar Association

NAACP

I think it's the teamster union

The interest group that is probably most concerned with the number of hours considered a full-time work week is the Teamsters Union, as it is the only labor-related interest group of the list.

Explanation:

The International Brotherhood of Teamsters is the union of transport workers and the largest single trade union in the United States.

IBT has approximately 1.4 million contributing members and 400,000 retirees, making it one of the largest single trade unions in the world.

Initially, the Teamsters were just a lorry driver union, but expanded into the general transport workers' union, reaching into the food industry today.