A Student Asked a Statistics Professor If Grades Were Marked

A student asked a statistics professor if grades were marked "on the curve." The professor decided
To give the student a project to determine if last year's statistics grades were normally distributed.
The professor told the student that last year's mean mark was 70 with a standard deviation of 10
And to use the following results.
What is the alternative hypothesis?

A) The letter grades are evenly distributed.
B) The letter grades are not evenly distributed.
C) The letter grades are normally distributed.
D) The letter grades are not normally distributed.
E) The letter grades are unfairly distributed.