Your question is Three-Way Handshake. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
How does the 3-way handshake work?
Explain the TCP connection setup sequence, including what each packet proves and why three steps are needed instead of two. Keep the answer at the protocol level, not a product-specific implementation detail.