A profession is best defined as:

A profession is best defined as the application of specialized knowledge in a way that benefits others, which highlights the ethical aspect of many professions. Beyond merely having advanced education or training, a profession typically involves a commitment to serving the needs of a community or the public. This reflects the understanding that the knowledge and skills acquired are not just for personal gain, but are used in service to others, which is a fundamental characteristic of professions like medicine, nursing, teaching, and even the field of radiology.

This definition emphasizes the importance of social responsibility and ethical conduct in professional practice, distinguishing professions from regular jobs where the primary goal may be profit or compensation. While other options touch on components of a profession, such as specialization or education, they do not encompass the underlying principle of societal benefit that is a core aspect of professional practice.