Zone is a physical description, not a perceived visual description. Any time you're talking about zones, areas, physical sizes of properties, etc you're talking about a virtual line drawn on the ground. You're not talking about "seeing."

You said everyone got it wrong. So what did the teacher say the right answer is? Did the teacher provide proven facts?

Whether you called me out or not, I said "when you pass the sign" and you said "100% sure about that?" I read that as an insinuation that I was incorrect.