What is causing this issue?

An engineer is addressing a connectivity issue between two servers where the remote server is unable to establish a successful session. Initial checks show that the remote server is not receiving an SYN-ACK while establishing a session by sending the first SYN .

What is causing this issue?
A . incorrect TCP handshake
B . incorrect UDP handshake
C . incorrect OSI configuration
D . incorrect snaplen configuration

Answer: A

Explanation:

Reference: https://www.sciencedirect.com/topics/computer-science/three-way-handshake#:~:text=The%20TCP%20handshake,as%20shown%20in%20Figure%203.8