I have some very straightforward questions about this.

Based on what I've heard, major significant mistakes usually warrant a D while minor significant ones warrant a C-.

However, since it is a must for every school to dish out at least a few C-, does this mean that:

1. Performance grades in a school are based on a bell-curve? Also, for grade C, how many different segregations of performance are there (e.g. is it 1.25/1.5/1.75?)?

2. If you're in a "chiong" school, simply doing the bare satisfactory minimum (no significant mistakes made) may also warrant a C- because others are seen to be performing better?

3. Has there been any past cases where an individual felt that the given grade was unfair or poorly justified, and tried to dispute?

Thank you