Explanation
https://docs.citrix.com/en-us/citrix-adc/current-release/global-server-load-balancing/how-to/protect-setup-agains
"if you enable multiple IP responses (MIR), the Citrix ADC appliance sends the best GSLB service as the first record in the response and adds the remaining active services as extra records. "

Explanation
answer: B. An HTTP-ECV monitor with the keyword in the Basic Parameters - Receive String field Short Explanation with reference:
An HTTP-ECV (Extended Content Verification) monitor is a type of monitor that allows the Citrix ADC appliance to check the health and availability of the web servers by sending HTTP requests and verifying the responses. An HTTP-ECV monitor can be configured with different parameters, such as Send String, Receive String, and Reverse, to customize the monitoring behavior. The Send String parameter specifies the HTTP request line that the monitor sends to the server. The Receive String parameter specifies the expected response from the server that indicates a successful probe. The Reverse parameter specifies whether to mark the service as UP or DOWN based on the presence or absence of the Receive String in the response.
In this scenario, the administrator needs to create a custom monitor that will look for a specific keyword response from the website, which will be used to keep services in an UP state. To meet this requirement, the administrator can create an HTTP-ECV monitor with the keyword in the Basic Parameters - Receive String field. This will make the monitor expect the keyword in the response from the server, and mark the service as UP if it finds it. The other options are incorrect, as they either use the wrong parameter or the wrong option for the monitoring task. For example, option A uses the Special Parameters - Receive String field, which is not a valid parameter for an HTTP-ECV monitor. Option C uses the Reverse option, which will make the monitor mark the service as DOWN if it finds the keyword in the response. Option D uses the Basic Parameters - Send String field, which will make the monitor send the keyword to the server, instead of looking for it in the response.
Configuring monitors | NetScaler : How to Configure an HTTP-ECV Monitor on a NetScaler Appliance - Citrix Customer Support : How to Configure Extended Content Verification (ECV) Monitors on NetScaler - Citrix Customer Support

Explanation
answer: A. Set the primary Citrix ADC to stay primary in the Configure HA Node settings and B. Set the secondary Citrix ADC to stay secondary in the Configure HA Node settings.
Short Explanation with reference:
When configuring a Citrix ADC high availability (HA) pair, the administrator can use the Configure HA Node settings to specify the preferred role of each node in the pair, either primary or secondary. This can prevent unwanted failovers or configuration synchronization issues, such as the one described in the scenario. By setting the primary Citrix ADC to stay primary and the secondary Citrix ADC to stay secondary, the administrator can ensure that the existing configuration on the primary node is preserved and replicated to the secondary node, and that the roles of the nodes are not reversed. The stayprimary and staysecondary options can be enabled or disabled by using the -stayPrimary and -staySecondary parameters in the CLI or by checking or unchecking the Stay Primary and Stay Secondary check-boxes in the GUI.
Therefore, the correct answer is A. Set the primary Citrix ADC to stay primary in the Configure HA Node settings and B. Set the secondary Citrix ADC to stay secondary in the Configure HA Node settings.
Configuring high availability node parameters | NetScaler

Explanation
https://docs.citrix.com/en-us/citrix-adc/current-release/system/high-availability-introduction/troubleshooting-hig

Explanation
https://docs.citrix.com/en-us/citrix-adc/current-release/appexpert/policies-and-expressions/adv-policy-exp-worki