The answer is D: The achievement of a high level of skill in the discipline in which the pro trained.
Explanation for each option:
A. Only doing what is required and not being a team player - This option is incorrect because professionalism often involves going beyond the minimum requirements and includes being a team player. Professionalism encompasses qualities such as collaboration, communication, and contributing positively to a team environment.
B. Graduating with honors from a program of study - While graduating with honors is an achievement, it is not a critical feature of professionalism. Professionalism is more about how one conducts oneself in a professional setting rather than academic achievements.
C. Doing enough without burning out - This option is not entirely incorrect, as maintaining a work-life balance is important. However, it does not capture the essence of professionalism, which involves consistently demonstrating competence, integrity, and ethical behavior.
D. The achievement of a high level of skill in the discipline in which the pro trained - This is the correct answer because professionalism involves attaining and maintaining a high level of skill and competence in one's field. It includes ongoing professional development and a commitment to excellence in practice.