What mechanism identifies the Zero Trust Exchange node for Zscaler Tunnels?

The correct choice is that the PAC file used in the Application Profile identifies the Zero Trust Exchange node for Zscaler Tunnels. The PAC (Proxy Auto-Configuration) file plays a crucial role in directing traffic for users within a Zero Trust architecture. It defines rules that the client's browser can follow to determine whether to route traffic through the Zscaler service or directly to the destination.

In the context of identifying the Zero Trust Exchange node, the PAC file effectively guides the endpoint on where to send traffic based on destination URLs or IP addresses. This mechanism enables Zscaler to inspect traffic in line with Zero Trust principles, ensuring that the right policies are applied based on the context of the user and their requests.

The other options pertain to configurations that do not specifically address the identification of the Zero Trust Exchange node. The Machine Key relates to application identity and security, while IP ranges and other configurations defined in the profiles assist in broader network management but do not pinpoint the specific nodes used for tunneling.