Final answer:
The correct answer is D) direct installation, which involves simultaneously turning off the old system and turning on the new system without any overlap, also called the 'big bang' approach.
Step-by-step explanation:
When an organization shifts from an old information system to a new one by turning off the old system as the new system is turned on, it is known as a direct installation.
Direct installation, also referred to as the 'big bang' approach, is a strategy whereby the legacy system is deactivated and the new system is activated simultaneously. This method can be efficient because it involves no overlap time, however, it is also risky because there is no fallback if issues arise with the new system.
Contrary to direct installation, parallel installation involves running both the old and new systems concurrently to ensure the new system works as expected before the old one is retired. This method can be efficient because it involves no overlap time, however, it is also risky because there is no fallback if issues arise with the new system. Contrary to direct installation, parallel installation involves running both the old and new systems concurrently to ensure the new system works as expected before the old one is retired.