Which option is the Cisco recommended method to secure access to the console port?
A. Configure the activation-character command.
B. Configure a very short timeout (less than 100 milliseconds) for the port.
C. Set the privilege level to a value less than 15.
D. Configure an ACL.
I agree, the ideal answer is not there, but from the con line perspective you are not able to configure an ACL. an ACL on another server doesn’t give it physical security.
A gives it in some way, where you would need to know (or type all characters to find out), what the activation key is.
There is no good answer here. From 300-115 CCNP Switch OCG page 425:
Secure the switch console: In many environments, switches are locked away in wiring closets where physical security is used to keep people from connecting to the switch console. Even so, you always should configure authentication on any switch console. It is usually appropriate to use the same authentication configuration on the console as the virtual terminal (vty) lines.
I would choose D as the console port can be accessed from a device such as a remote access router acting as a reverse telnet server. An ACL can be configured on this reverse telnet server.