Questions like this can be tricky! Be sure to note the wording of the question. The interviewers want to see how you navigate controversial topics-- but are not necessarily asking for your opinion on them. Indiana University School of Medicine has a Frequently Asked Questions section on its website that discusses this topic to a certain degree. They mention that they recognize the fact that "free intellectual inquiry, debate, and constructive dialogue are vital to the university's academic mission and must be protected even when the views expressed are unpopular or controversial." They further describe how their policy is meant to neither prescribe nor inhibit discussions of controversial, complex, or sensitive matters.

Discuss how you remain tactful when controversial topics arise, showing your communication skills and ability to handle the pressures of uncomfortable and controversial conversations.