Can someone check over my work?

Hello, I'm new to onshape and learning it. I've been going through the course "Part Design Using Part Studios (Deprecated)" and recently completed the Exercise "Wheel Rim". But when I check the mass, mine doesn't match up with any of the answer choices provided at the self-check at the end of the exercise on the website. I dont even know where to start looking for my error, so that's why I'm here. Can someone check over my work and tell me what error I made, or at the very least give me a hint of what step I made my error at and/or tell me how to look for errors? Thanks in advance!

Link to my work: https://cad.onshape.com/documents/e90016223756a12fa5199fc3/w/a31c349f660b1009aadc143f/e/d8dbea06020c797faed773fb