What is one of the components of Cisco Application Centric Infrastructure (ACI)?

One of the key components of Cisco Application Centric Infrastructure (ACI) is the Application Policy Infrastructure Controller (APIC). The APIC serves as the centralized management and automation tool for the ACI environment. It enables the provisioning, management, and monitoring of the network infrastructure that supports application requirements.

The APIC uses an application-centric approach, allowing organizations to define application policies which ensure that the infrastructure can adjust to meet the performance, security, and operational needs of those applications seamlessly. It integrates with various network components and facilitates communication among them, translating the business policies into network configurations. This greatly enhances agility and reduces the complexity often associated with traditional network management.

In contrast, the other options represent different technologies or concepts that, while important in their respective areas, do not directly align with the core components of Cisco ACI. Network Function Virtualization refers generally to the virtualized instances of network services, while the Virtual Router Redundancy Protocol is used for router failover. Software-Defined Access is a broader technology paradigm that does not specifically pertain to ACI.