Answer:
A
Explanation:
Answer A. Logically speaking there is no fair chance unless they use all the names but we can rule out C by the higher chance of students crowding, B is less likely as selecting winners from students who arrive first would be nearly the same as who bought their tickets first. D, selecting a grade excludes (estimating) around 1500 students or more from being included. A is the only logical answer left and by dividing them randomly you give everyone a full chance.