Answer:
a. human; obtaining informed consent
Step-by-step explanation:
Any research that involves the participation of human subjects follows strict guidelines so that the study may not end up in harm effects. For such research involving human subject, informed consent is obtained from the humans. Such informed consent must be true whereby participants reveal actions, emotions and behaviors through the research questions. Sometimes deception is used by researchers by misleading participants with the purpose of keeping the feasibility the research, but there is a limit to it so that no harmful effect on participants borne out of deception could be realized. In research where deception is used, human participants must get the outline of the conclusion which must be true based on honest information. This is informed consent.