Refer to the exhibit.

For connecting the MMCS-A to the customer management network in a Dell VPLEX system, it is essential to use the correct port that is designated for management traffic. According to the Dell EMC VPLEX documentation1, each MMCS (Management Module Control Station) has two network connections that connect to the customer’s network. One of these is used for system monitoring and remote connectivity for Dell Technologies Customer Support, and the other is for use by the Network Address Translation (NAT) Gateway.

In the context of the VS6 VPLEX cluster, the management ports are located on MMCS-A and MMCS-B, and both must be configured and connected to the customer network. MMCS-A is the management port that will be accessed for all management and monitoring purposes1. Therefore, the cable that should be connected to the customer management network is the one associated with MMCS-A.

Based on the information provided in the search results and the description of the image, the correct cable to connect to the customer management network for MMCS-A is indicated by the letter B in the exhibit. This connection is crucial for enabling management and monitoring access to the VPLEX system.