How important are final semester grades?

I was accepted to UVA this year. Throughout high school, I had mostly As with a few A-s and only 1 B+. However, this semester I had a major case of senioritis as well as dealing with some other stuff. Now I have almost all Bs. My parents tell me I need to work harder or my admission will be rescinded. Should I be worried or are my parents just trying to scare me into being less lazy?

I think you should be fine