'Define trustable root certificates S/Mime configuration - during Installation

I’m installing gpg4win and ran into a popup that wasn’t shown on the step by step screenshots in Compendium. (see screenshot attachment)

I’m not sure how to respond.

I’ve never used any email security program, other than perhaps clicking on links to secure email from a bank & an insurance company. I’m not sure if I’ll ever use or need S/Mime, but would like to have it as an option “just in case”. I have no security certificates or whatever to input and have no idea how to configure it even if I did.