According to the Citrix documentation2, the SDX platform is a multi-tenant appliance that supports multiple Citrix ADC instances. Each instance is fully isolated and has its own dedicated resources. The SDX platform allows administrators to create, manage, and monitor multiple instances from a single management interface.

The administrator should negate the expression of the Responder policy to avoid the HTTP callout recursion issue. According to the Citrix documentation, "If you configure an HTTP callout policy that is bound globally, you must ensure that the policy expression does not match the callout request. Otherwise, the callout request will trigger the policy, resulting in a callout recursion." The expression in option B ensures that the policy does not match the callout request by adding the NOT operator at the end.
https://docs.citrix.com/en-us/citrix-adc/13/appexpert/http-callout/http-callout-policy.html

According to the Citrix documentation1, the Citrix ADC SDX appliance allows administrators to upgrade the Citrix ADC instances on an individual basis, without affecting the other instances or the SDX appliance. This allows the instances to run different firmware versions and provides flexibility and convenience for the administrator.

According to the Citrix Virtual Apps and Desktops 7 Deployment and Administration course, the Citrix ADC maintains a revision history of the configuration files, which can be used to restore a previous configuration in case of accidental changes or deletions. Restarting the Citrix ADC, running HA file synchronization, or running Save v/s Running configuration will not undo the changes made by the administrator. Therefore, the correct answer is A. Restore from revision history1
1: Manage | Citrix Virtual Apps and Desktops 7 2308

According to the Citrix documentation, the Operator command policy grants full access to all features except shell access, user configuration, and partition configuration. The Sysadmin command policy grants full access to all features except shell access. The Network command policy grants full access to all features except shell access and user configuration. The Superuser command policy grants full access to all features, including shell access. Therefore, the Operator command policy is the best option for the scenario.