What is the best reason why you deserve an a grade

If you feel that your teacher didn’t fully appreciate your work, then start by talking to them about your work, not the grade. Ask them to help you understand how they read your work, and how you might perform better in the future. During this discussion, you can find out why they felt your answers didn’t deserve the grade that a better answer would warrant. If you then feel that you should receive a higher grade, discuss this. If you demand something, you’ve lost already, and if it devolves into an argument, then you’ve lost. Your teacher probably has a lot more training and experience in debate and argumentation. They also have authority and expertise that you lack, and a reputation that is more complicated and deeper than your own.

Three things I have learned: one, that you should only object when a grade is of critical importance, and two, that grades are designed to push the student to a deeper understanding.