First, it would help to know what kinds of grades you are getting, what your parents expect to see, grade wise. Also, it would help to know if you can honestly say you are doing your best. That means, are you prepared? Are you studying? Are you doing your homework? Are you asking for help when you need help? Is it in one subject or more? Do you need help in the subject?
That is what we (my husband and I) ask (consider) when it comes to grades. We know that our daughter is doing her best and she’s getting good grades. If she started to slip – we would examine what was going on and see how we could help her.
When I was in HS, I was a straight A student, until Latin. I hovered at a C, improved to a B. I struggled, it just was something that escaped me, my parents did see me doing my best – and were happy with the B. I worked my butt off to get that B – an A, really wasn’t in me, maybe if it was a full year course, but not as a semester. I did my best, they understood.
Is it possible that they don’t feel that you are trying hard enough?