Which is NOT a transport layer vulnerability?

Which is NOT a transport layer vulnerability?

• Unauthorized network access
• The vulnerability that allows "fingerprints" and other enumeration of host information
• Mishandling of undefined, poorly defined
• Overloading transport-layer mechanisms 

EXPLANATION

The different vulnerabilities of the Transport layer are mishandling of undefined, poorly defined,
Vulnerability that allow “fingerprinting” & other enumeration of host information, Overloading of transport-layer mechanisms etc. Unauthorized network access is an example of physical layer vulnerability.