Exam CISA topic 1 question 859 discussion

Given these considerations, the first component to restore should be A. Operating System. This is because the operating system forms the basic layer of the computing environment, enabling the restoration and functioning of all other components, including applications and data backups. Once the operating system is in place, data backups can be restored, and applications necessary for critical business operations can be set up and configured.

Logically OS should come first how can you access data without interaction. Depending on the type of site we can choose what do we need first. Here is not saying anything about that so we should believe that OS will come first.

Depending on whether the alternate site is a warm or cold site, the alternate site is usually focused on returning backups, not on doing things like restoring from the OS.

A. Operating system

Data backups (B): Data is usually the most critical asset for an organization. Therefore, restoring data backups is often the first step in disaster recovery. This ensures that important data is available for use as soon as possible. Operating system (A): Once data is restored, the next priority is to bring up the operating system. The operating system is necessary to run applications and provide a platform for other services. Applications (D): After the operating system is in place, applications can be restored. This includes essential business applications that the organization relies on to function. Decision support system (C): Decision support systems, while important, are typically of lower priority compared to data, operating systems, and essential applications. They can be restored after the core infrastructure and critical applications are up and running.

I'm pretty sure that backups do NOT come before OS.