Answer: No, I do not think this policy is fair.
Step-by-step explanation:
I do not think that students must maintain a "C" average in order to participate in after school activities, due to the fact that students will be able to get extra help and also maintain a healthy balance between work and fun.
First of all, students would be able to get extra help from extra after school activities. For example, if the student is struggling with Maths, he or she could enter an extra curricular maths club to help bring their grades higher. This would really help as learning maths outside of school costs quite a bit of money, so it would allow the students to learn more and also save money at the same time.
However, what if the activity is not related to schoolwork and grades at all, like football or basketball? Well, this would also benefit the student, helping them to maintain a healthy balance between work and fun, allowing the student to clear their mind and relax. Being stressed is a huge problem, and is usually one of the major issues that cause bad grades. This would allow the student maybe even get better grades in school.
Therefore, I don't think that students should have to maintain a "C" average in order to participate in after school activities, as students would be able to get extra help and maintain a healthy balance between work and fun.