Enable alerts for loopback requests

Could someone please enlighten me what the behavior of CFP is when this option is not activated and no rules are defined for an application?

a) All loopback requests are passed through
b) All loopback requests are blocked

Hopefully it’s option a) and b) only takes effect when the alert is activated.

it will allow all 127.0.0.1 traffic.
if you enable it it will ask you what you would like to do with it.