What approach should a client use to set up a globally distributed Adobe Experience Manager 6.1 environment?

In the context of setting up a globally distributed Adobe Experience Manager 6.1 environment, utilizing TARMK (TAM or Targeting, Analytics, and Resource Management Kit) for clustering is particularly effective due to its specialized components for managing distributed content delivery and ensuring that all components are aligned with global best practices for performance and reliability.

TARMK provides tools that enable better resource management across multiple geographical locations, ensuring that content is delivered efficiently regardless of where the user is located. This is especially crucial for environments that require high availability and scalability, as is often the case with global deployments. By leveraging TARMK, organizations can optimize their Adobe Experience Manager instances to handle larger traffic and improve content replication across the distributed architecture.

The other options do not provide the same level of support for globally distributed environments. Utilizing CRX2 or CRX3 focuses on the specific repository implementations without the comprehensive resource management and distribution capabilities that TARMK offers. Setting up clustering with MongoDB is also a valid approach in certain contexts, but it may not encapsulate all the needs of a sophisticated and highly available global setup in the way TARMK is designed to do.