Explanation
According to the Citrix Secure Web Gateway 12.1 documentation1, Citrix Secure Web Gateway (SWG) is a cloud-delivered service that provides secure access to web and SaaS applications, globally. It provides a complete stack of security capabilities, such as Secure Web Gateway, Cloud Access Security Broker, Malware Protection with Sandboxing, Intrusion Prevention and Detection Systems, and Data Loss Prevention. Citrix SWG can intercept and inspect all the traffic, including SSL/TLS, coming in and going out of the enterprise network. It can also block access to URLs identified as serving harmful or insecure content, and identify users who are accessing malicious websites. Citrix SWG can be deployed as a proxy on a Citrix ADC appliance at the edge of the network. The other options are not relevant for this scenario, as they do not provide the same level of security and visibility as Citrix SWG.