What does ExternalZone represent in the presented rule?

A.
The Internet.

B.
Interfaces that administrator has defined to be part of External Security Zone.

C.
External interfaces on all security gateways.

D.
External interfaces of specific gateways.

Explanation:
Configuring Interfaces
Configure the Security Gateway 80 interfaces in the Interfaces tab in the Security Gateway window.
To configure the interfaces:
1. From the Devices window, double-click the Security Gateway 80.
The Security Gateway window opens.
2. Select the Interfaces tab.
3. Select Use the following settings. The interface settings open.
4. Select the interface and click Edit.
The Edit window opens.
5. From the IP Assignment section, configure the IP address of the interface:
1. Select Static IP.
2. Enter the IP address and subnet mask for the interface.
6. In Security Zone, select Wireless, DMS, External, or Internal. Security zone is a type of zone, created by a
bridge to easily create segments, while maintaining IP addresses and router configurations. Security zones let
you choose if to enable or not the firewall between segments.
https://sc1.checkpoint.com/documents/R76/CP_R76_SmartProvisioning_WebAdmin/16741.htm