Final answer:
The event that increased public attention to the IRB system was the Tuskegee Syphilis Study (B), which involved the unethical treatment of African-American men in a study on syphilis without their informed consent.
Step-by-step explanation:
The incident that brought increased public attention to the problems with the Institutional Review Board (IRB) system was B) The Tuskegee Syphilis Study. This unethical syphilis study was conducted on African-American men in Alabama from 1932 to 1972, without providing them with the known treatment and without their informed consent. The public outrage following the media exposure of the study's details contributed to a significant shift in research ethics and the creation of stricter guidelines for the protection of human subjects in scientific research.
The Tuskegee experiment led directly to the National Research Act of 1974, which established the requirement for IRBs at institutions conducting human subject research. IRBs are committees that review research proposals involving human participants to ensure ethical standards are upheld, which include considerations for participants' health, well-being, autonomy, and life. This ensures that contemporary studies avoid the past exploitations that occurred in trials like the Tuskegee study.