When children are research participants, __________.

When children are research participants, it is essential to obtain informed consent from their parents or others who act on their behalf. This is to ensure that the child's rights and well-being are protected during the research process. Informed consent is a fundamental ethical principle in research involving children, as they may not have the capacity to fully understand the implications of their participation. Choice A is incorrect because seeking the opinion of others when in doubt about harmful effects is not a substitute for informed consent. Choice B is incorrect because children do not have an absolute right to conceal their identity in research, especially when it comes to ensuring their safety and well-being. Choice C is incorrect as it is important to inform children or their parents about the results of the research to maintain transparency and respect for their participation.