Which components should an architect recommend be used to meet the secure remote access requirements while ensuring high availability?

Deploying only one of each component (NetScaler, StoreFront, Delivery Controller) at each datacenter creates a single point of failure for secure remote access and session management within each location, which does not meet high availability requirements.

This option limits the deployment of these critical components to only the London datacenter, failing to provide secure remote access and high availability for a global XenDesktop implementation.

Deploying two NetScalers (Citrix Gateways), two StoreFront servers, and two Delivery Controllers in each of three datacenters provides a total of six of each component, ensuring high availability and redundancy for secure remote access and session brokering across all sites. This configuration eliminates single points of failure for authentication, resource enumeration, and session launching in every datacenter.

This option indicates NetScalers only in the London datacenter, which would prevent users in other global datacenters from gaining secure remote access to their virtual desktops and applications.