The Environmental Settings within the Workspace Environment Management (WEM) Administration Console are indeed per machine, not per user, meaning that these settings affect all users on the machine uniformly. Additionally, multiple configuration sets are needed when different global settings are required for different agents. This allows for more tailored management of various agent groups within the WEM environment. Therefore, the correct answers are that the Environmental Settings within the WEM Administration Console are per machine, not per user, and multiple configuration sets are needed for different global settings for various agents.

To minimize attacks like ransomware, phishing, and session hijacking without interfering with user productivity, the engineer can implement HTTP Strict Transport Security (HSTS) and use HTTP response headers to send security policies to endpoint browsers. HSTS ensures that browsers connect to websites over HTTPS, which secures the communication and prevents certain types of attacks. Using HTTP response headers to send security policies helps enforce security measures directly on the user's browser, providing additional protection without requiring changes to the user's behavior or disabling any essential functionality.

A Citrix App Layering recipe is a documented sequence of steps for integrating applications into Citrix App Layering. It provides detailed instructions on how to layer applications, which allows administrators to efficiently manage and deploy applications within the Citrix environment.

The correct answer is 'PersistentDictionary.edb'. This file is used to store a subscription on the Storefront server. The subscriptions are stored in the PersistentDictionary.edb file located in the C:\Windows\ServiceProfiles\NetworkService\AppData\Roaming\Citrix\SubscriptionsStore\ folder.