I answered "I wear pants and a sweatshirt," but it said it was incorrect. English is my first language, and in the US saying pants is the same as saying trousers (although pants is way more common). I think pants should also be a correct answer because many people will get this wrong and be confused if this isn't changed. Sorry if you already decided on this and haven't changed it yet.
Once again Jellei saves the day(see his comment below). The explanation of the two plurals confused the heck out of me until I saw Jellei's explanation. I would have grasped it so much more easily had it been explained as: masculine-personal versus everything else. Virile captures that nicely.
I'm a native Polish, not English speaker, but it's probably one of the best known differences between British and American English. In British English the word pants means underpants and trousers is what you refer to as pants. Check out this video https://www.youtube.com/watch?v=CX8s98_BMRA, actually the whole channel is pretty interesting.
Keep in mind that the variation of English taught in Polish schools is British English, so naturally trousers was probably the word that fisrt came to mind. On the other hand, American English is probably more widespread in popculture (movies, tv series, music), so sometimes we might unintentionally be mixing the two variations (at least I might).
True. It's just that "bluza" is a very... general word. English is a lot more specific with this item.
You can specify "hoodie" by saying "bluza z kapturem" (with a hood). But if it just has a hood but it's not important at the moment to mention it, then you just say "bluza".
Yes, it can translate to "pants" if you're thinking in American English. But we used "trousers" here (in the main English sentence) because a big portion of learners (those that prefer British English) will think of something else when they see this sentence and we want to be as unambigous as possible.
Your answer is correct and accepted, it must have been some bug if it was rejected.