Can anyone explain why A is correct and D isn't? It seems they are expressing the same thing (even though I know that can't be true)

My freshman year I had an incident with drinking and got on probation with my school. I just called the office of student conduct to ask if it would show up on my transcript or any materials that get sent to law schools. They told me no and that the only time they report an incident to a school is if they reach out for a "background check sort of thing." Even in that case, they only report "major" incidents. I asked if probation is considered a major incident and he said no. To clarify even further I asked if my probation would be reported to law schools if they reached out and he said "no probation isn't considered a major incident."

Based off his answers, I don't think I need to write an addendum. I'm just so worried that somehow law schools will find out and in the case I didn't write one, I'm screwed. On the other hand, if I write one and they don't find out, I also screwed myself. I know you're supposed to write an addendum about any incident you had, but if it's not being reported, do I need to? I really don't know what to do here. I don't want to write about a drinking incident if I don't have to. But I also don't want it to bite me in the butt.