Final answer:
The American Psychological Association's ethical guidelines require informed consent, the option to withdraw, and risk disclosure, but not necessarily financial compensation for participants. The answer is option C.
Step-by-step explanation:
According to the ethical guidelines of the American Psychological Association, researchers using human subjects must do several things to ensure the ethical treatment of their participants. These include providing subjects the opportunity to withdraw from the study at any time without penalty, warning the subjects if any risks exist to those participating in the study, and explaining the study in detail so that subjects can make an informed decision about whether to participate.
However, providing adequate financial reimbursement to compensate for the time and effort of their subjects is not a mandatory ethical requirement according to these guidelines, although it may be considered a best practice in some circumstances.