Application independence refers to:

• A. Separation or decoupling of data from application systems
• B. Tight coupling of data and applications
• C. Data can be replaced only if applications are updated
• D. Applications must always be replaced with data storage

Answer: (A)

Application independence is about keeping the data layer separate from the applications that use it, so you can change or replace applications without having to rewrite or reorganize the data. When data is decoupled, access is through stable interfaces and schemas, and the same data can be shared by multiple applications or migrated to new systems without major changes. This decoupling is what enables flexibility and longevity in a IT environment.

Tight coupling would bind data and applications together, making changes to one require changes to the other. The idea that data can be replaced only if applications are updated implies dependency, not independence, and the notion that applications must be replaced with data storage suggests a misfit with how independence is intended to work.