Currently you select a category that only has one option, then have to ALSO select that one option, imo it should be when you select a category, especially if there is only one option, it then just selected that for you.

I understand when you first open some of these NPC shops they have cute UI and so its fine to not do that right away, but once you select a category the cute UI vanishes anyways so I think the most QoL friendly option is that it does this automatically (and probably just in all situations it defaults to the first valid option, and maybe doesn't even offer the null / none option as.. it's not really a useful option).

Thanks for reading