The correct answer is social loafing.
Social loafing refers to the phenomenon where a person puts in less effort to achieve a goal, when he/she is part of a group, compared to when he/she is working alone. Social loafing usually occurs due to diffusion of responsibility, where a person feels less responsible and motivated to help out, when he/she is in a group with other people. In this instance, Carlene demonstrates that she dislikes social loafing because she believes that when working in a group, there is always going to be someone who is content to sit back and let others do the work.