Explanation
Virtual private networks (VPNs) are commonly used to allow access into trust zones. Via a VPN, access can be controlled and logged and only allowed through secure channels by authorized users. It also adds an additional layer of encryption and protection to communications.

Explanation/Reference:
Explanation:
The standards put out by Building Industry Consulting Service International (BICSI) primarily cover complex cabling designs and setups for data centers, but also include specifications on power, energy efficiency, and hot/cold aisle setups.

In order for any archiving system to be deemed useful and compliant, regular tests must be performed to ensure the data can still be recovered and accessible, should it ever be needed, for the duration of the retention requirements.

Application virtualization is a software implementation that allows applications and programs to run in an isolated environment rather than directly interacting with the operating system. Sandboxing refers to segregating information or processes for security or testing purposes, but it's not directly related to isolation from the underlying operating system. Abstracting sounds similar to the correct term but is not pertinent to the question, and hosting is provided as an erroneous answer.