A scientist has noted a possible relationship between a certain chemical

substance found in fish and the occurrence of kidney failure in humans. Which of the following preliminary steps should the scientist take before conducting a controlled experiment?

a)Establish a cause-and-effect relationship between the substance and the outcome.

b)Review the literature to determine what other research is available on this topic.

c)Write research Grant proposal to the appropriate Federal funding agency.

d)Distribute letters of consent to human subjects who will be used in the research.