Can someone sympathize with me here?

I can't explain the anger I want to show to my parents right now. When they just saw my first term report card, they were both mad as hell. I mean, in my progress report I got a failure warning and they were mad, but this time I raised my grade to a C on History and they're still infuriated! I mean, they just can't appreciate the hard work I tried to do in History! School is hard enough without them pestering me about my grades! It's not like I can suddenly get an A from an F!