What implies a person's frustration towards coworkers?

The choice indicating that a person often feels frustrated is correct because it directly captures the essence of the emotional state being addressed in the question. Frustration towards coworkers generally manifests when an individual faces repeated challenges or conflicts in interactions, leading to feelings of annoyance or dissatisfaction. This choice succinctly encapsulates that ongoing emotional response, suggesting that such frustration is a common experience for that person within their work environment.

Comparatively, the other options convey positive sentiments related to collaboration and teamwork, which do not align with the notion of frustration. Enjoying collaboration and finding teamwork fulfilling reflect a willingness and positive attitude towards working with others, while high tolerance levels suggest patience and the ability to endure difficult situations without frustration. These concepts contrast sharply with the idea of feeling frustrated, as they focus instead on proactive engagement and satisfaction in cooperative endeavors. Thus, option C correctly highlights the negative aspect of the individual's experience.