The headline feels wrong, as the author started by laying out their assumptions, and revised after more or less getting their question answered. One could just

The headline feels wrong, as the author started by laying out their assumptions, and revised after more or less getting their question answered. One could just as easily form this as a question. “All three are usually at the application layer in my experience. Would you like me to discuss this, or give you a more general mapping?” In either case, asking questions before answering is something any good interviewer should be looking for as a positive signal. A general knowledge question like this, though, seems designed for a quick answer, so I’d only ask the question if I was really confused rather than splitting hairs.