Which port allows a security analyst to read traffic without private keys?

The correct choice allows a security analyst to read traffic without requiring private keys because it involves traffic that is typically unencrypted. Port 110 is used for Post Office Protocol version 3 (POP3), which is commonly utilized for retrieving email from a remote server. POP3 operates primarily in plaintext, meaning the emails transmitted and received do not involve encryption mechanisms that would require private keys for decryption.

In contrast, other ports listed correspond to protocols that often prioritize secure communication. Port 25 is predominantly used for sending email via Simple Mail Transfer Protocol (SMTP) but is generally accompanied by security measures, especially in modern implementations. Port 80 is associated with Hypertext Transfer Protocol (HTTP), which does not inherently include encryption but has largely been overshadowed by its secure counterpart. Port 443 is used for HTTPS, which encrypts data in transit, rendering it unreadable without the appropriate decryption keys.

Therefore, the ability to read unencrypted traffic on Port 110 aligns with the nature of the protocol and the typical usage for transmitting emails without additional security layers, making it the appropriate choice for this scenario.