A Citrix Administrator deploys a new Citrix ADC MPX appliance in the demilitarized zone (DMZ),...

Correct Answer: B. Two-arm

Short Explanation with reference:

A two-arm deployment is a common scenario where the Citrix ADC appliance has two network interfaces, one connected to the DMZ network and the other connected to the internal network1. This allows the appliance to act as a gateway between the two networks and provide load balancing, security, and optimization features for the applications hosted on the internal servers2. A two-arm deployment also provides better isolation and protection for the internal network than a one-arm deployment, where the appliance has only one network interface connected to a switch or router that spans both networks3. A transparent mode is a packet forwarding mode that enables the appliance to act as a Layer 2 device and bridge packets that are not destined for it4. A forward proxy mode is a feature that enables the appliance to act as an intermediary between clients and servers on the internet, caching web content and applying policies. Neither of these modes are relevant for the scenario described in the question.

1: Citrix ADC at a Glance 2: Tech Paper: Best practices for NetScaler ADC Deployments 3: Configure a Citrix ADC BLX appliance with a network mode 4: Packet forwarding modes | NetScaler 14.1 : Configuring Forward Proxy | NetScaler 14.1