What must the IACUC ensure regarding alternatives to painful procedures?

The correct choice focuses on the IACUC's responsibility to ensure that researchers are actively considering alternatives to painful or distressing procedures involving animals. This is a crucial aspect of animal welfare and ethical research practices mandated by regulations such as the Animal Welfare Act and the National Institutes of Health (NIH) guidelines.

When the IACUC reviews a protocol, it must confirm that the principal investigator has thoroughly evaluated all possible alternatives to reduce or eliminate pain and distress. This includes ensuring that any written assurance demonstrates that alternatives are not available or that no other less invasive methods exist to achieve the research objectives. This process is integral to promoting ethical research practices and minimizing unnecessary suffering of animals used in research.

Overall, the IACUC plays a vital role in enforcing the 3Rs principle: Replacement, Reduction, and Refinement. By ensuring that alternatives to painful procedures are considered, the IACUC helps advance animal welfare while allowing for scientific progress.