Which of the Following Is a Common Ethical Guideline Suggested

Which of the following is a common ethical guideline suggested by the American Psychological Association?

A) Participants must be informed of the nature of the research in clearly understandable language.
B) Debriefing may be omitted when young children are involved.
C) Participants cannot be subjected to any physically or emotionally painful stimuli
D) Participants may not withdraw once they start.