The organization or business unit that relies on the application is the correct answer because that entity bears the business and legal accountability for the application data and for decisions about how it is classified, retained, shared, and disclosed.

The organization or business unit that relies on the application defines the purpose of the data, owns the risk and compliance obligations, and sets access and retention policies. The development team and operations teams provide technical capabilities and the governance roles provide oversight, but ownership of the data usually rests with the business function that uses and depends on it.

The software development team is incorrect because developers build and maintain the application and its features but they are typically custodians of code and technical artifacts rather than the business owners who decide how data is used or disclosed.

The IT operations or platform team is incorrect because operations teams are responsible for availability, performance, and technical protection of systems and they act as custodians who implement controls rather than as the business owners who set data policy and bear legal obligations.

The Chief Data Officer or an appointed data steward is incorrect in the general case because these roles usually provide governance, standards, and stewardship across the enterprise. They may be delegated ownership for certain data domains in some organizations but they most often act to support or represent the business unit that retains the primary ownership.

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