For top-level classes that's true, and nto only does it not make sense, the compiler will not even allow the use of those modifiers.
Have a look at this page on access modifiers, and try to figure out why that is.
Build a man a fire, and he'll be warm for a day. Set a man on fire, and he'll be warm for the rest of his life.
Think about what it would mean if they were allowed.
For example, private. What would a private class mean? It would probably be a class that was not visible to any other class. So what use would it be? Can you think of a situation where you would want that?
This is often the best way to go about resolving any queries along the lines of "why isn't that modifier allowed here". Think about what the effect would be if it was allowed, and when you might need that. Usually it just wouldn't make sense.