Answer:
Obtain a waiver of documentation of informed consent.
Step-by-step explanation:
According to Ethical standards and procedures for research with human subjects, All researchers need to notify the subjects in case the procedures that they are about to conduct can potentially create harmful effect to the subjects during and after the research.
To pursue such research, the researchers need to specifically explain the Dangers/Risks to the subjects and obtain a waiver of consent that the subjects sign willingly , without any coercion.
(Offering money as an incentives to subjects in such case is Allowed since it's not considered as coercion)