You will only find incoming email attachments on the Links tab IF the following box (within the Retrieval tab of email settings) is checked (I show it highlighted, but unchecked below):
While this box is checked by default (with a new GM installation) we most often recommend folks UNCHECK this box. Over the years, we find most people are frustrated by the fact that checking this box ends up with LOTS of undesired files linked via the Links tab, as doing so includes email signature files, graphics, background images from emails, etc., far more than what you and I would considered a typical email "attachment".
We generally recommend, if you want something on the Links tab, deliberately put it there (such as your item B in your A/B list above).
Hope this feedback helps. Please let me know if I need to clarify anything.