Explanation/Reference: https://docs.citrix.com/en-us/citrix-adc/current-release/appexpert/policies-and-expressions/ introduction-to-policies-and-exp/classic-and-advanced-policy.html

Explanation
answer: A. The GSLB services will be marked as DOWN if the MEP connection has been DOWN for
10 seconds.
Short Explanation with reference: The GSLBSvcStateDelayTime parameter is used to set the amount of delay in updating the state of GSLB service to DOWN when MEP goes down1. This parameter is applicable only if monitors are not bound to GSLB services1. By default, the value of this parameter is 0, which means that the GSLB service state is updated immediately when MEP goes down1. However, if the value of this parameter is set to a positive number, such as 10, then the GSLB service state is updated after that number of seconds when MEP goes down1. This can help avoid unnecessary disruption of services due to temporary MEP failures2.
Therefore, the effect of the above command on the GSLB environment is that the GSLB services will be marked as DOWN if the MEP connection has been DOWN for 10 seconds. The other options are incorrect because they either do not involve the GSLBSvcStateDelayTime parameter or they do not reflect the correct relationship between MEP and GSLB service state. The correct answer is A. The GSLB services will be marked as DOWN if the MEP connection has been DOWN for 10 seconds.

Explanation
answer: A. MAC-based forwarding (MBF)
Short Explanation with reference:
MAC-based forwarding (MBF) is a mode on a Citrix ADC that can be used to avoid asymmetrical packet flows and multiple route/ARP lookups. MBF enables the Citrix ADC to forward packets based on the MAC address of the destination server, instead of the IP address. This way, the Citrix ADC does not need to perform routing or ARP resolution for each packet, which reduces the processing overhead and improves performance.
MBF also ensures that the return traffic from the server follows the same path as the incoming traffic from the client, which avoids asymmetrical routing issues.
MBF can be enabled on a Citrix ADC by using the GUI or the CLI of the appliance. MBF can be applied to a specific service or a service group, or to all services on the appliance. MBF can also be used in conjunction with other features, such as direct server return (DSR) and link load balancing (LLB).
Therefore, option A is the correct answer.
References:
[MAC-Based Forwarding]
[Configuring MAC-Based Forwarding]
[How to Configure MAC Based Forwarding on NetScaler Appliance]