For me i believe that if the rule changes it changes, but if i was the principle I would make it a C average for many different reasons. Not all kids have the same perfect parents as others. Some kids come home to different life styles, one kid may come home to an abusive father, another may come home to a sick mother than needs to be taken care of. They may have problems that you can't solve that will ultimately effect their grade. They could be great students but when they come home to an abusive father that will break them down mentally they may not have the strength to pick them selves up to do their homework, or the strength to get themselves out of bed and get made fun of at school. It just wouldn't be fair to the kids that try there best even with their family circumstances. Sports may be the only thing to take their pain away, and if they cant bring their grade up to a B average and they get kicked off the team, it could change the paths that they take in life and possibly cause them to rebel. As a principle you have to think about the kids. You have to think worst case scenario.

To do unto yourselves as you do to others, or to love your neighbor as yourself. Its the golden rule, but it is disappearing in schools not only with students but with teachers also. The principle needs to look at changing this average very closely. She needs to pretend hat she is a parent that has a child with a C average and picture that he is a great athlete and sports is all he has. I believe that this letter would change her opinion on things and hopefully help her realize that Something as small as this could have a huge impact on someone's life.