Final answer:
The American Psychological Association (APA) sets ethical guidelines for professionals in the mental health field in the United States.
Step-by-step explanation:
The organization that determines the guidelines setting the moral standard for those practicing in the mental health field is the American Psychological Association (APA). The APA is a professional organization representing psychologists in the United States, and it develops and enforces ethical guidelines for its members.
These guidelines are designed to ensure that psychologists act professionally and ethically in their work.