The third alternative is correct.
Stakeholders are associations of people who have an interest in common and who work to ensure that their interests are considered by the public authority. This is an inherent policy issue. Thus, there are several interest groups for the most diverse subjects. The scientific community and its research groups can also be considered as interest groups, as they will seek to organize themselves politically to defend the needs of their category. For example, a fertility research group can organize to require more resources for research in that area.
